Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

13 files changed, 1482 insertions, 0 deletions

diff --git a/third_party/libwebrtc/build/android/bytecode/BUILD.gn b/third_party/libwebrtc/build/android/bytecode/BUILD.gn
new file mode 100644
index 0000000000..8d717eb0ad
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/BUILD.gn
@@ -0,0 +1,86 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+java_binary("bytecode_processor") {
+  main_class = "org.chromium.bytecode.ByteCodeProcessor"
+  wrapper_script_name = "helper/bytecode_processor"
+  deps = [ ":bytecode_processor_java" ]
+}
+
+java_library("bytecode_processor_java") {
+  sources = [
+    "java/org/chromium/bytecode/ByteCodeProcessor.java",
+    "java/org/chromium/bytecode/ClassPathValidator.java",
+    "java/org/chromium/bytecode/TypeUtils.java",
+  ]
+  deps = [
+    "//third_party/android_deps:org_ow2_asm_asm_java",
+    "//third_party/android_deps:org_ow2_asm_asm_util_java",
+  ]
+  enable_bytecode_checks = false
+}
+
+# A bytecode rewriter that replaces all calls to
+# `FragmentActivity Fragment.getActivity()` with
+# `Activity Fragment.getActivity()`.
+java_binary("fragment_activity_replacer") {
+  main_class = "org.chromium.bytecode.FragmentActivityReplacer"
+  deps = [ ":fragment_activity_replacer_java" ]
+  wrapper_script_name = "helper/fragment_activity_replacer"
+}
+
+# A bytecode rewriter that replaces all calls to
+# `FragmentActivity Fragment.getActivity()` with
+# `Activity Fragment.getActivity()`  followed by a cast to FragmentActivity.
+# Prefer :fragment_activity_replacer. This rewriter should only be used for
+# libraries that rely on getActivity() returning a FragmentActivity *and* are
+# not going to be used in an app that contains multiple copies of the AndroidX
+# Fragment library (i.e. WebLayer).
+java_binary("fragment_activity_replacer_single_androidx") {
+  main_class = "org.chromium.bytecode.FragmentActivityReplacer"
+  deps = [ ":fragment_activity_replacer_java" ]
+  wrapper_script_name = "helper/fragment_activity_replacer_single_androidx"
+  wrapper_script_args = [ "--single-androidx" ]
+}
+
+java_library("fragment_activity_replacer_java") {
+  visibility = [ ":*" ]
+  sources = [
+    "java/org/chromium/bytecode/ByteCodeRewriter.java",
+    "java/org/chromium/bytecode/FragmentActivityReplacer.java",
+  ]
+  deps = [
+    "//third_party/android_deps:org_ow2_asm_asm_commons_java",
+    "//third_party/android_deps:org_ow2_asm_asm_java",
+    "//third_party/android_deps:org_ow2_asm_asm_util_java",
+  ]
+}
+
+java_binary("trace_event_adder") {
+  main_class = "org.chromium.bytecode.TraceEventAdder"
+  deps = [ ":trace_event_adder_java" ]
+  wrapper_script_name = "helper/trace_event_adder"
+}
+
+java_library("trace_event_adder_java") {
+  visibility = [ ":*" ]
+  sources = [
+    "java/org/chromium/bytecode/ByteCodeRewriter.java",
+    "java/org/chromium/bytecode/EmptyOverrideGeneratorClassAdapter.java",
+    "java/org/chromium/bytecode/MethodCheckerClassAdapter.java",
+    "java/org/chromium/bytecode/MethodDescription.java",
+    "java/org/chromium/bytecode/ParentMethodCheckerClassAdapter.java",
+    "java/org/chromium/bytecode/TraceEventAdder.java",
+    "java/org/chromium/bytecode/TraceEventAdderClassAdapter.java",
+    "java/org/chromium/bytecode/TraceEventAdderMethodAdapter.java",
+  ]
+  deps = [
+    ":bytecode_processor_java",
+    "//third_party/android_deps:org_ow2_asm_asm_commons_java",
+    "//third_party/android_deps:org_ow2_asm_asm_java",
+    "//third_party/android_deps:org_ow2_asm_asm_util_java",
+  ]
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ByteCodeProcessor.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ByteCodeProcessor.java
new file mode 100644
index 0000000000..b767f4f089
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ByteCodeProcessor.java
@@ -0,0 +1,167 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import org.objectweb.asm.ClassReader;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+/**
+ * Java application that takes in an input jar, performs a series of bytecode
+ * transformations, and generates an output jar.
+ */
+class ByteCodeProcessor {
+    private static final String CLASS_FILE_SUFFIX = ".class";
+    private static final int BUFFER_SIZE = 16384;
+    private static boolean sVerbose;
+    private static boolean sIsPrebuilt;
+    private static ClassLoader sDirectClassPathClassLoader;
+    private static ClassLoader sFullClassPathClassLoader;
+    private static Set<String> sFullClassPathJarPaths;
+    private static Set<String> sMissingClassesAllowlist;
+    private static Map<String, String> sJarToGnTarget;
+    private static ClassPathValidator sValidator;
+
+    private static Void processEntry(ZipEntry entry, byte[] data) {
+        ClassReader reader = new ClassReader(data);
+        if (sIsPrebuilt) {
+            sValidator.validateFullClassPath(
+                    reader, sFullClassPathClassLoader, sMissingClassesAllowlist);
+        } else {
+            sValidator.validateDirectClassPath(reader, sDirectClassPathClassLoader,
+                    sFullClassPathClassLoader, sFullClassPathJarPaths, sMissingClassesAllowlist,
+                    sVerbose);
+        }
+        return null;
+    }
+
+    private static void process(String gnTarget, String inputJarPath)
+            throws ExecutionException, InterruptedException {
+        ExecutorService executorService =
+                Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
+        try (ZipInputStream inputStream = new ZipInputStream(
+                     new BufferedInputStream(new FileInputStream(inputJarPath)))) {
+            while (true) {
+                ZipEntry entry = inputStream.getNextEntry();
+                if (entry == null) {
+                    break;
+                }
+                byte[] data = readAllBytes(inputStream);
+                executorService.submit(() -> processEntry(entry, data));
+            }
+            executorService.shutdown(); // This is essential in order to avoid waiting infinitely.
+            executorService.awaitTermination(1, TimeUnit.HOURS);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+
+        if (sValidator.hasErrors()) {
+            sValidator.printAll(gnTarget, sJarToGnTarget);
+            System.exit(1);
+        }
+    }
+
+    private static byte[] readAllBytes(InputStream inputStream) throws IOException {
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        int numRead = 0;
+        byte[] data = new byte[BUFFER_SIZE];
+        while ((numRead = inputStream.read(data, 0, data.length)) != -1) {
+            buffer.write(data, 0, numRead);
+        }
+        return buffer.toByteArray();
+    }
+
+    /**
+     * Loads a list of jars and returns a ClassLoader capable of loading all classes found in the
+     * given jars.
+     */
+    static ClassLoader loadJars(Collection<String> paths) {
+        URL[] jarUrls = new URL[paths.size()];
+        int i = 0;
+        for (String path : paths) {
+            try {
+                jarUrls[i++] = new File(path).toURI().toURL();
+            } catch (MalformedURLException e) {
+                throw new RuntimeException(e);
+            }
+        }
+        return new URLClassLoader(jarUrls);
+    }
+
+    /**
+     * Extracts a length-encoded list of strings from the arguments, and adds them to |out|. Returns
+     * the new "next index" to be processed.
+     */
+    private static int parseListArgument(String[] args, int index, Collection<String> out) {
+        int argLength = Integer.parseInt(args[index++]);
+        out.addAll(Arrays.asList(Arrays.copyOfRange(args, index, index + argLength)));
+        return index + argLength;
+    }
+
+    public static void main(String[] args) throws ClassPathValidator.ClassNotLoadedException,
+                                                  ExecutionException, InterruptedException {
+        // Invoke this script using //build/android/gyp/bytecode_processor.py
+        int currIndex = 0;
+        String gnTarget = args[currIndex++];
+        String inputJarPath = args[currIndex++];
+        sVerbose = args[currIndex++].equals("--verbose");
+        sIsPrebuilt = args[currIndex++].equals("--is-prebuilt");
+
+        sMissingClassesAllowlist = new HashSet<>();
+        currIndex = parseListArgument(args, currIndex, sMissingClassesAllowlist);
+
+        ArrayList<String> sdkJarPaths = new ArrayList<>();
+        currIndex = parseListArgument(args, currIndex, sdkJarPaths);
+
+        ArrayList<String> directClassPathJarPaths = new ArrayList<>();
+        directClassPathJarPaths.add(inputJarPath);
+        directClassPathJarPaths.addAll(sdkJarPaths);
+        currIndex = parseListArgument(args, currIndex, directClassPathJarPaths);
+        sDirectClassPathClassLoader = loadJars(directClassPathJarPaths);
+
+        ArrayList<String> fullClassPathJarPaths = new ArrayList<>();
+        currIndex = parseListArgument(args, currIndex, fullClassPathJarPaths);
+        ArrayList<String> gnTargets = new ArrayList<>();
+        parseListArgument(args, currIndex, gnTargets);
+        sJarToGnTarget = new HashMap<>();
+        assert fullClassPathJarPaths.size() == gnTargets.size();
+        for (int i = 0; i < fullClassPathJarPaths.size(); ++i) {
+            sJarToGnTarget.put(fullClassPathJarPaths.get(i), gnTargets.get(i));
+        }
+
+        // Load all jars that are on the classpath for the input jar for analyzing class
+        // hierarchy.
+        sFullClassPathJarPaths = new HashSet<>();
+        sFullClassPathJarPaths.add(inputJarPath);
+        sFullClassPathJarPaths.addAll(sdkJarPaths);
+        sFullClassPathJarPaths.addAll(fullClassPathJarPaths);
+        sFullClassPathClassLoader = loadJars(sFullClassPathJarPaths);
+        sFullClassPathJarPaths.removeAll(directClassPathJarPaths);
+
+        sValidator = new ClassPathValidator();
+        process(gnTarget, inputJarPath);
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ByteCodeRewriter.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ByteCodeRewriter.java
new file mode 100644
index 0000000000..37b0e86348
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ByteCodeRewriter.java
@@ -0,0 +1,101 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.ClassWriter;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+import java.util.zip.ZipOutputStream;
+
+/**
+ * Base class for scripts that perform bytecode modifications on a jar file.
+ */
+public abstract class ByteCodeRewriter {
+    private static final String CLASS_FILE_SUFFIX = ".class";
+
+    public void rewrite(File inputJar, File outputJar) throws IOException {
+        if (!inputJar.exists()) {
+            throw new FileNotFoundException("Input jar not found: " + inputJar.getPath());
+        }
+        try (InputStream inputStream = new BufferedInputStream(new FileInputStream(inputJar))) {
+            try (OutputStream outputStream = new FileOutputStream(outputJar)) {
+                processZip(inputStream, outputStream);
+            }
+        }
+    }
+
+    /** Returns true if the class at the given path in the archive should be rewritten. */
+    protected abstract boolean shouldRewriteClass(String classPath);
+
+    /**
+     * Returns true if the class at the given {@link ClassReader} should be rewritten.
+     */
+    protected boolean shouldRewriteClass(ClassReader classReader) {
+        return true;
+    }
+
+    /**
+     * Returns the ClassVisitor that should be used to modify the bytecode of class at the given
+     * path in the archive.
+     */
+    protected abstract ClassVisitor getClassVisitorForClass(
+            String classPath, ClassVisitor delegate);
+
+    private void processZip(InputStream inputStream, OutputStream outputStream) {
+        try (ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream)) {
+            ZipInputStream zipInputStream = new ZipInputStream(inputStream);
+            ZipEntry entry;
+            while ((entry = zipInputStream.getNextEntry()) != null) {
+                ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+                boolean handled = processClassEntry(entry, zipInputStream, buffer);
+                if (handled) {
+                    ZipEntry newEntry = new ZipEntry(entry.getName());
+                    zipOutputStream.putNextEntry(newEntry);
+                    zipOutputStream.write(buffer.toByteArray(), 0, buffer.size());
+                } else {
+                    zipOutputStream.putNextEntry(entry);
+                    zipInputStream.transferTo(zipOutputStream);
+                }
+            }
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private boolean processClassEntry(
+            ZipEntry entry, InputStream inputStream, OutputStream outputStream) {
+        if (!entry.getName().endsWith(CLASS_FILE_SUFFIX) || !shouldRewriteClass(entry.getName())) {
+            return false;
+        }
+        try {
+            ClassReader reader = new ClassReader(inputStream);
+            ClassWriter writer = new ClassWriter(reader, ClassWriter.COMPUTE_FRAMES);
+            ClassVisitor classVisitor = writer;
+            if (shouldRewriteClass(reader)) {
+                classVisitor = getClassVisitorForClass(entry.getName(), writer);
+            }
+            reader.accept(classVisitor, ClassReader.EXPAND_FRAMES);
+
+            writer.visitEnd();
+            byte[] classData = writer.toByteArray();
+            outputStream.write(classData, 0, classData.length);
+            return true;
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ClassPathValidator.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ClassPathValidator.java
new file mode 100644
index 0000000000..9f45df5117
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ClassPathValidator.java
@@ -0,0 +1,233 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import org.objectweb.asm.ClassReader;
+
+import java.io.PrintStream;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import java.util.function.Consumer;
+
+/**
+ * Checks classpaths (given as ClassLoaders) by reading the constant pool of the class file and
+ * attempting to load every referenced class. If there are some that are unable to be found, it
+ * stores a helpful error message if it knows where it might find them, and exits the program if it
+ * can't find the class with any given classpath.
+ */
+public class ClassPathValidator {
+    // Number of warnings to print.
+    private static final int MAX_MISSING_CLASS_WARNINGS = 10;
+    // Number of missing classes to show per missing jar.
+    private static final int MAX_ERRORS_PER_JAR = 2;
+    // Map of missing .jar -> Missing class -> Classes that failed.
+    // TreeMap so that error messages have sorted list of jars.
+    private final Map<String, Map<String, Set<String>>> mDirectErrors =
+            Collections.synchronizedMap(new TreeMap<>());
+    // Missing classes we only track the first one for each jar.
+    // Map of missingClass -> srcClass.
+    private final Map<String, String> mMissingClasses =
+            Collections.synchronizedMap(new TreeMap<>());
+
+    static class ClassNotLoadedException extends ClassNotFoundException {
+        private final String mClassName;
+
+        ClassNotLoadedException(String className, Throwable ex) {
+            super("Couldn't load " + className, ex);
+            mClassName = className;
+        }
+
+        public String getClassName() {
+            return mClassName;
+        }
+    }
+
+    private static void validateClass(ClassLoader classLoader, String className)
+            throws ClassNotLoadedException {
+        if (className.startsWith("[")) {
+            // Dealing with an array type which isn't encoded nicely in the constant pool.
+            // For example, [[Lorg/chromium/Class$1;
+            className = className.substring(className.lastIndexOf('[') + 1);
+            if (className.charAt(0) == 'L' && className.endsWith(";")) {
+                className = className.substring(1, className.length() - 1);
+            } else {
+                // Bailing out if we have an non-class array type.
+                // This could be something like [B
+                return;
+            }
+        }
+        if (className.matches(".*\\bR(\\$\\w+)?$")) {
+            // Resources in R.java files are not expected to be valid at this stage in the build.
+            return;
+        }
+        if (className.matches("^libcore\\b.*")) {
+            // libcore exists on devices, but is not included in the Android sdk as it is a private
+            // API.
+            return;
+        }
+        try {
+            classLoader.loadClass(className.replace('/', '.'));
+        } catch (ClassNotFoundException e) {
+            throw new ClassNotLoadedException(className, e);
+        } catch (NoClassDefFoundError e) {
+            // We assume that this is caused by another class that is not going to able to be
+            // loaded, so we will skip this and let that class fail with ClassNotFoundException.
+        }
+    }
+
+    /**
+     * Given a .class file, see if every class referenced in the main class' constant pool can be
+     * loaded by the given ClassLoader.
+     *
+     * @param classReader .class file interface for reading the constant pool.
+     * @param classLoader classpath you wish to validate.
+     * @param errorConsumer Called for each missing class.
+     */
+    private static void validateClassPath(ClassReader classReader, ClassLoader classLoader,
+            Consumer<ClassNotLoadedException> errorConsumer) {
+        char[] charBuffer = new char[classReader.getMaxStringLength()];
+        // According to the Java spec, the constant pool is indexed from 1 to constant_pool_count -
+        // 1. See https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.4
+        for (int i = 1; i < classReader.getItemCount(); i++) {
+            int offset = classReader.getItem(i);
+            // Class entries correspond to 7 in the constant pool
+            // https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.4
+            if (offset > 0 && classReader.readByte(offset - 1) == 7) {
+                try {
+                    validateClass(classLoader, classReader.readUTF8(offset, charBuffer));
+                } catch (ClassNotLoadedException e) {
+                    errorConsumer.accept(e);
+                }
+            }
+        }
+    }
+
+    public void validateFullClassPath(ClassReader classReader, ClassLoader fullClassLoader,
+            Set<String> missingClassAllowlist) {
+        // Prebuilts only need transitive dependencies checked, not direct dependencies.
+        validateClassPath(classReader, fullClassLoader, (e) -> {
+            if (!missingClassAllowlist.contains(e.getClassName())) {
+                addMissingError(classReader.getClassName(), e.getClassName());
+            }
+        });
+    }
+
+    public void validateDirectClassPath(ClassReader classReader, ClassLoader directClassLoader,
+            ClassLoader fullClassLoader, Collection<String> jarsOnlyInFullClassPath,
+            Set<String> missingClassAllowlist, boolean verbose) {
+        validateClassPath(classReader, directClassLoader, (e) -> {
+            try {
+                validateClass(fullClassLoader, e.getClassName());
+            } catch (ClassNotLoadedException d) {
+                if (!missingClassAllowlist.contains(e.getClassName())) {
+                    addMissingError(classReader.getClassName(), e.getClassName());
+                }
+                return;
+            }
+            if (verbose) {
+                System.err.println("Class \"" + e.getClassName()
+                        + "\" not found in direct dependencies,"
+                        + " but found in indirect dependiences.");
+            }
+            // Iterating through all jars that are in the full classpath but not the direct
+            // classpath to find which one provides the class we are looking for.
+            for (String jarPath : jarsOnlyInFullClassPath) {
+                try {
+                    ClassLoader smallLoader =
+                            ByteCodeProcessor.loadJars(Collections.singletonList(jarPath));
+                    validateClass(smallLoader, e.getClassName());
+                    addDirectError(jarPath, classReader.getClassName(), e.getClassName());
+                    break;
+                } catch (ClassNotLoadedException f) {
+                }
+            }
+        });
+    }
+
+    private void addMissingError(String srcClass, String missingClass) {
+        mMissingClasses.put(missingClass, srcClass);
+    }
+
+    private void addDirectError(String jarPath, String srcClass, String missingClass) {
+        synchronized (mDirectErrors) {
+            Map<String, Set<String>> failedClassesByMissingClass = mDirectErrors.get(jarPath);
+            if (failedClassesByMissingClass == null) {
+                // TreeMap so that error messages have sorted list of classes.
+                failedClassesByMissingClass = new TreeMap<>();
+                mDirectErrors.put(jarPath, failedClassesByMissingClass);
+            }
+            Set<String> failedClasses = failedClassesByMissingClass.get(missingClass);
+            if (failedClasses == null) {
+                failedClasses = new TreeSet<>();
+                failedClassesByMissingClass.put(missingClass, failedClasses);
+            }
+            failedClasses.add(srcClass);
+        }
+    }
+
+    public boolean hasErrors() {
+        return !mDirectErrors.isEmpty() || !mMissingClasses.isEmpty();
+    }
+
+    private static void printValidationError(
+            PrintStream out, String gnTarget, Map<String, Set<String>> missingClasses) {
+        out.print(" * ");
+        out.println(gnTarget);
+        int i = 0;
+        // The list of missing classes is non-exhaustive because each class that fails to validate
+        // reports only the first missing class.
+        for (Map.Entry<String, Set<String>> entry : missingClasses.entrySet()) {
+            String missingClass = entry.getKey();
+            Set<String> filesThatNeededIt = entry.getValue();
+            out.print("     * ");
+            if (i == MAX_ERRORS_PER_JAR) {
+                out.print(String.format(
+                        "And %d more...", missingClasses.size() - MAX_ERRORS_PER_JAR));
+                break;
+            }
+            out.print(missingClass.replace('/', '.'));
+            out.print(" (needed by ");
+            out.print(filesThatNeededIt.iterator().next().replace('/', '.'));
+            if (filesThatNeededIt.size() > 1) {
+                out.print(String.format(" and %d more", filesThatNeededIt.size() - 1));
+            }
+            out.println(")");
+            i++;
+        }
+    }
+
+    public void printAll(String gnTarget, Map<String, String> jarToGnTarget) {
+        String streamer = "=============================";
+        System.err.println();
+        System.err.println(streamer + " Dependency Checks Failed " + streamer);
+        System.err.println("Target: " + gnTarget);
+        if (!mMissingClasses.isEmpty()) {
+            int i = 0;
+            for (Map.Entry<String, String> entry : mMissingClasses.entrySet()) {
+                if (++i > MAX_MISSING_CLASS_WARNINGS) {
+                    System.err.println(String.format("... and %d more.",
+                            mMissingClasses.size() - MAX_MISSING_CLASS_WARNINGS));
+                    break;
+                }
+                System.err.println(String.format(
+                        "Class \"%s\" not found on any classpath. Used by class \"%s\"",
+                        entry.getKey(), entry.getValue()));
+            }
+            System.err.println();
+        }
+        if (!mDirectErrors.isEmpty()) {
+            System.err.println("Direct classpath is incomplete. To fix, add deps on:");
+            for (Map.Entry<String, Map<String, Set<String>>> entry : mDirectErrors.entrySet()) {
+                printValidationError(
+                        System.err, jarToGnTarget.get(entry.getKey()), entry.getValue());
+            }
+            System.err.println();
+        }
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/EmptyOverrideGeneratorClassAdapter.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/EmptyOverrideGeneratorClassAdapter.java
new file mode 100644
index 0000000000..d0957625d7
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/EmptyOverrideGeneratorClassAdapter.java
@@ -0,0 +1,103 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import static org.objectweb.asm.Opcodes.ACC_ABSTRACT;
+import static org.objectweb.asm.Opcodes.ACC_INTERFACE;
+import static org.objectweb.asm.Opcodes.ALOAD;
+import static org.objectweb.asm.Opcodes.ASM7;
+import static org.objectweb.asm.Opcodes.ILOAD;
+import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
+import static org.objectweb.asm.Opcodes.IRETURN;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Type;
+
+import java.util.ArrayList;
+
+class EmptyOverrideGeneratorClassAdapter extends ClassVisitor {
+    private final ArrayList<MethodDescription> mMethodsToGenerate;
+    private String mSuperClassName;
+    private boolean mIsAbstract;
+    private boolean mIsInterface;
+
+    public EmptyOverrideGeneratorClassAdapter(
+            ClassVisitor cv, ArrayList<MethodDescription> methodsToGenerate) {
+        super(ASM7, cv);
+        mMethodsToGenerate = methodsToGenerate;
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName,
+            String[] interfaces) {
+        super.visit(version, access, name, signature, superName, interfaces);
+
+        mSuperClassName = superName;
+        mIsAbstract = (access & ACC_ABSTRACT) == ACC_ABSTRACT;
+        mIsInterface = (access & ACC_INTERFACE) == ACC_INTERFACE;
+    }
+
+    @Override
+    public void visitEnd() {
+        if (mIsAbstract || mIsInterface || mMethodsToGenerate.isEmpty()) {
+            super.visitEnd();
+            return;
+        }
+
+        for (MethodDescription method : mMethodsToGenerate) {
+            if (!method.shouldCreateOverride) {
+                continue;
+            }
+
+            MethodVisitor mv = super.visitMethod(
+                    method.access, method.methodName, method.description, null, null);
+            writeOverrideCode(mv, method.access, method.methodName, method.description);
+        }
+
+        super.visitEnd();
+    }
+
+    /**
+     * Writes code to a method to call that method's parent implementation.
+     * <pre>
+     * {@code
+     * // Calling writeOverrideCode(mv, ACC_PUBLIC, "doFoo", "(Ljava/lang/String;)I") writes the
+     * following method body: public int doFoo(String arg){ return super.doFoo(arg);
+     * }
+     * }
+     * </pre>
+     *
+     * This will be rewritten later by TraceEventAdderClassAdapter to wrap the body in a trace
+     * event.
+     */
+    private void writeOverrideCode(
+            MethodVisitor mv, final int access, final String name, final String descriptor) {
+        Type[] argTypes = Type.getArgumentTypes(descriptor);
+        Type returnType = Type.getReturnType(descriptor);
+
+        mv.visitCode();
+
+        // Variable 0 contains `this`, load it into the operand stack.
+        mv.visitVarInsn(ALOAD, 0);
+
+        // Variables 1..n contain all arguments, load them all into the operand stack.
+        int i = 1;
+        for (Type arg : argTypes) {
+            // getOpcode(ILOAD) returns the ILOAD equivalent to the current argument's type.
+            mv.visitVarInsn(arg.getOpcode(ILOAD), i);
+            i += arg.getSize();
+        }
+
+        // Call the parent class method with the same arguments.
+        mv.visitMethodInsn(INVOKESPECIAL, mSuperClassName, name, descriptor, false);
+
+        // Return the result.
+        mv.visitInsn(returnType.getOpcode(IRETURN));
+
+        mv.visitMaxs(0, 0);
+        mv.visitEnd();
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/FragmentActivityReplacer.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/FragmentActivityReplacer.java
new file mode 100644
index 0000000000..a40f39c4ce
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/FragmentActivityReplacer.java
@@ -0,0 +1,238 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.commons.MethodRemapper;
+import org.objectweb.asm.commons.Remapper;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Java application that modifies Fragment.getActivity() to return an Activity instead of a
+ * FragmentActivity, and updates any existing getActivity() calls to reference the updated method.
+ *
+ * See crbug.com/1144345 for more context.
+ */
+public class FragmentActivityReplacer extends ByteCodeRewriter {
+    private static final String GET_ACTIVITY_METHOD_NAME = "getActivity";
+    private static final String GET_LIFECYCLE_ACTIVITY_METHOD_NAME = "getLifecycleActivity";
+    private static final String NEW_METHOD_DESCRIPTOR = "()Landroid/app/Activity;";
+    private static final String OLD_METHOD_DESCRIPTOR =
+            "()Landroidx/fragment/app/FragmentActivity;";
+    private static final String REQUIRE_ACTIVITY_METHOD_NAME = "requireActivity";
+    private static final String SUPPORT_LIFECYCLE_FRAGMENT_IMPL_BINARY_NAME =
+            "com.google.android.gms.common.api.internal.SupportLifecycleFragmentImpl";
+
+    public static void main(String[] args) throws IOException {
+        // Invoke this script using //build/android/gyp/bytecode_rewriter.py
+        if (!(args.length == 2 || args.length == 3 && args[0].equals("--single-androidx"))) {
+            System.err.println("Expected arguments: [--single-androidx] <input.jar> <output.jar>");
+            System.exit(1);
+        }
+
+        if (args.length == 2) {
+            FragmentActivityReplacer rewriter = new FragmentActivityReplacer(false);
+            rewriter.rewrite(new File(args[0]), new File(args[1]));
+        } else {
+            FragmentActivityReplacer rewriter = new FragmentActivityReplacer(true);
+            rewriter.rewrite(new File(args[1]), new File(args[2]));
+        }
+    }
+
+    private final boolean mSingleAndroidX;
+
+    public FragmentActivityReplacer(boolean singleAndroidX) {
+        mSingleAndroidX = singleAndroidX;
+    }
+
+    @Override
+    protected boolean shouldRewriteClass(String classPath) {
+        return true;
+    }
+
+    @Override
+    protected ClassVisitor getClassVisitorForClass(String classPath, ClassVisitor delegate) {
+        ClassVisitor invocationVisitor = new InvocationReplacer(delegate, mSingleAndroidX);
+        switch (classPath) {
+            case "androidx/fragment/app/Fragment.class":
+                return new FragmentClassVisitor(invocationVisitor);
+            case "com/google/android/gms/common/api/internal/SupportLifecycleFragmentImpl.class":
+                return new SupportLifecycleFragmentImplClassVisitor(invocationVisitor);
+            default:
+                return invocationVisitor;
+        }
+    }
+
+    /**
+     * Updates any Fragment.getActivity/requireActivity() or getLifecycleActivity() calls to call
+     * the replaced method.
+     */
+    private static class InvocationReplacer extends ClassVisitor {
+        private final boolean mSingleAndroidX;
+
+        private InvocationReplacer(ClassVisitor baseVisitor, boolean singleAndroidX) {
+            super(Opcodes.ASM7, baseVisitor);
+            mSingleAndroidX = singleAndroidX;
+        }
+
+        @Override
+        public MethodVisitor visitMethod(
+                int access, String name, String descriptor, String signature, String[] exceptions) {
+            MethodVisitor base = super.visitMethod(access, name, descriptor, signature, exceptions);
+            return new MethodVisitor(Opcodes.ASM7, base) {
+                @Override
+                public void visitMethodInsn(int opcode, String owner, String name,
+                        String descriptor, boolean isInterface) {
+                    boolean isFragmentGetActivity = name.equals(GET_ACTIVITY_METHOD_NAME)
+                            && descriptor.equals(OLD_METHOD_DESCRIPTOR)
+                            && isFragmentSubclass(owner);
+                    boolean isFragmentRequireActivity = name.equals(REQUIRE_ACTIVITY_METHOD_NAME)
+                            && descriptor.equals(OLD_METHOD_DESCRIPTOR)
+                            && isFragmentSubclass(owner);
+                    boolean isSupportLifecycleFragmentImplGetLifecycleActivity =
+                            name.equals(GET_LIFECYCLE_ACTIVITY_METHOD_NAME)
+                            && descriptor.equals(OLD_METHOD_DESCRIPTOR)
+                            && owner.equals(SUPPORT_LIFECYCLE_FRAGMENT_IMPL_BINARY_NAME);
+                    if ((opcode == Opcodes.INVOKEVIRTUAL || opcode == Opcodes.INVOKESPECIAL)
+                            && (isFragmentGetActivity || isFragmentRequireActivity
+                                    || isSupportLifecycleFragmentImplGetLifecycleActivity)) {
+                        super.visitMethodInsn(
+                                opcode, owner, name, NEW_METHOD_DESCRIPTOR, isInterface);
+                        if (mSingleAndroidX) {
+                            super.visitTypeInsn(
+                                    Opcodes.CHECKCAST, "androidx/fragment/app/FragmentActivity");
+                        }
+                    } else {
+                        super.visitMethodInsn(opcode, owner, name, descriptor, isInterface);
+                    }
+                }
+
+                private boolean isFragmentSubclass(String internalType) {
+                    // Look up classes with a ClassLoader that will resolve any R classes to Object.
+                    // This is fine in this case as resource classes shouldn't be in the class
+                    // hierarchy of any Fragments.
+                    ClassLoader resourceStubbingClassLoader = new ClassLoader() {
+                        @Override
+                        protected Class<?> findClass(String name) throws ClassNotFoundException {
+                            if (name.matches(".*\\.R(\\$.+)?")) {
+                                return Object.class;
+                            }
+                            return super.findClass(name);
+                        }
+                    };
+
+                    // This doesn't use Class#isAssignableFrom to avoid us needing to load
+                    // AndroidX's Fragment class, which may not be on the classpath.
+                    try {
+                        String binaryName = Type.getObjectType(internalType).getClassName();
+                        Class<?> clazz = resourceStubbingClassLoader.loadClass(binaryName);
+                        while (clazz != null) {
+                            if (clazz.getName().equals("androidx.fragment.app.Fragment")) {
+                                return true;
+                            }
+                            clazz = clazz.getSuperclass();
+                        }
+                        return false;
+                    } catch (ClassNotFoundException e) {
+                        throw new RuntimeException(e);
+                    }
+                }
+            };
+        }
+    }
+
+    /**
+     * Updates the implementation of Fragment.getActivity() and Fragment.requireActivity().
+     */
+    private static class FragmentClassVisitor extends ClassVisitor {
+        private FragmentClassVisitor(ClassVisitor baseVisitor) {
+            super(Opcodes.ASM7, baseVisitor);
+        }
+
+        @Override
+        public MethodVisitor visitMethod(
+                int access, String name, String descriptor, String signature, String[] exceptions) {
+            // Update the descriptor of getActivity() and requireActivity().
+            MethodVisitor baseVisitor;
+            if (descriptor.equals(OLD_METHOD_DESCRIPTOR)
+                    && (name.equals(GET_ACTIVITY_METHOD_NAME)
+                            || name.equals(REQUIRE_ACTIVITY_METHOD_NAME))) {
+                // Some Fragments in a Clank library implement an interface that defines an
+                // `Activity getActivity()` method. Fragment.getActivity() is considered its
+                // implementation from a typechecking perspective, but javac still generates a
+                // getActivity() method in these Fragments that call Fragment.getActivity(). This
+                // isn't an issue when the methods return different types, but after changing
+                // Fragment.getActivity() to return an Activity, this generated implementation is
+                // now overriding Fragment's, which it can't do because Fragment.getActivity() is
+                // final. We make it non-final here to avoid this issue.
+                baseVisitor = super.visitMethod(
+                        access & ~Opcodes.ACC_FINAL, name, NEW_METHOD_DESCRIPTOR, null, exceptions);
+            } else {
+                baseVisitor = super.visitMethod(access, name, descriptor, signature, exceptions);
+            }
+
+            // Replace getActivity() with `return ContextUtils.activityFromContext(getContext());`
+            if (name.equals(GET_ACTIVITY_METHOD_NAME) && descriptor.equals(OLD_METHOD_DESCRIPTOR)) {
+                baseVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+                baseVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "androidx/fragment/app/Fragment",
+                        "getContext", "()Landroid/content/Context;", false);
+                baseVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, "org/chromium/utils/ContextUtils",
+                        "activityFromContext", "(Landroid/content/Context;)Landroid/app/Activity;",
+                        false);
+                baseVisitor.visitInsn(Opcodes.ARETURN);
+                // Since we set COMPUTE_FRAMES, the arguments of visitMaxs are ignored, but calling
+                // it forces ClassWriter to actually recompute the correct stack/local values.
+                // Without this call ClassWriter keeps the original stack=0,locals=1 which is wrong.
+                baseVisitor.visitMaxs(0, 0);
+                return null;
+            }
+
+            return new MethodRemapper(baseVisitor, new Remapper() {
+                @Override
+                public String mapType(String internalName) {
+                    if (internalName.equals("androidx/fragment/app/FragmentActivity")) {
+                        return "android/app/Activity";
+                    }
+                    return internalName;
+                }
+            });
+        }
+    }
+
+    /**
+     * Update SupportLifecycleFragmentImpl.getLifecycleActivity().
+     */
+    private static class SupportLifecycleFragmentImplClassVisitor extends ClassVisitor {
+        private SupportLifecycleFragmentImplClassVisitor(ClassVisitor baseVisitor) {
+            super(Opcodes.ASM7, baseVisitor);
+        }
+
+        @Override
+        public MethodVisitor visitMethod(
+                int access, String name, String descriptor, String signature, String[] exceptions) {
+            // SupportLifecycleFragmentImpl has two getActivity methods:
+            //   1. public FragmentActivity getLifecycleActivity():
+            //      This is what you'll see in the source. This delegates to Fragment.getActivity().
+            //   2. public Activity getLifecycleActivity():
+            //      This is generated because the class implements LifecycleFragment, which
+            //      declares this method, and delegates to #1.
+            //
+            // Here we change the return type of #1 and delete #2.
+            if (name.equals(GET_LIFECYCLE_ACTIVITY_METHOD_NAME)) {
+                if (descriptor.equals(OLD_METHOD_DESCRIPTOR)) {
+                    return super.visitMethod(
+                            access, name, NEW_METHOD_DESCRIPTOR, signature, exceptions);
+                }
+                return null;
+            }
+            return super.visitMethod(access, name, descriptor, signature, exceptions);
+        }
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/MethodCheckerClassAdapter.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/MethodCheckerClassAdapter.java
new file mode 100644
index 0000000000..5aef275319
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/MethodCheckerClassAdapter.java
@@ -0,0 +1,136 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import static org.objectweb.asm.ClassReader.EXPAND_FRAMES;
+import static org.objectweb.asm.Opcodes.ACC_ABSTRACT;
+import static org.objectweb.asm.Opcodes.ACC_INTERFACE;
+import static org.objectweb.asm.Opcodes.ASM7;
+
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+
+/**
+ * This ClassVisitor verifies that a class and its methods are suitable for rewriting.
+ * Given a class and a list of methods it performs the following checks:
+ * 1. Class is subclass of {@link android.view.View}.
+ * 2. Class is not abstract or an interface.
+ *
+ * For each method provided in {@code methodsToCheck}:
+ * If the class overrides the method then we can rewrite it directly.
+ * If the class doesn't override the method then we can generate an override with {@link
+ * EmptyOverrideGeneratorClassAdapter}, but first we must check if the parent method is private or
+ * final using {@link ParentMethodCheckerClassAdapter}.
+ *
+ * This adapter modifies the provided method list to indicate which methods should be overridden or
+ * skipped.
+ */
+class MethodCheckerClassAdapter extends ClassVisitor {
+    private static final String VIEW_CLASS_DESCRIPTOR = "android/view/View";
+
+    private final ArrayList<MethodDescription> mMethodsToCheck;
+    private final ClassLoader mJarClassLoader;
+    private String mSuperName;
+
+    public MethodCheckerClassAdapter(
+            ArrayList<MethodDescription> methodsToCheck, ClassLoader jarClassLoader) {
+        super(ASM7);
+        mMethodsToCheck = methodsToCheck;
+        mJarClassLoader = jarClassLoader;
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName,
+            String[] interfaces) {
+        super.visit(version, access, name, signature, superName, interfaces);
+
+        mSuperName = superName;
+
+        boolean isAbstract = (access & ACC_ABSTRACT) == ACC_ABSTRACT;
+        boolean isInterface = (access & ACC_INTERFACE) == ACC_INTERFACE;
+
+        if (isAbstract || isInterface || !isClassView(name)) {
+            mMethodsToCheck.clear();
+            return;
+        }
+    }
+
+    @Override
+    public MethodVisitor visitMethod(
+            int access, String name, String descriptor, String signature, String[] exceptions) {
+        if (mMethodsToCheck.isEmpty()) {
+            return super.visitMethod(access, name, descriptor, signature, exceptions);
+        }
+
+        for (MethodDescription method : mMethodsToCheck) {
+            if (method.methodName.equals(name) && method.description.equals(descriptor)) {
+                method.shouldCreateOverride = false;
+            }
+        }
+
+        return super.visitMethod(access, name, descriptor, signature, exceptions);
+    }
+
+    @Override
+    public void visitEnd() {
+        if (mMethodsToCheck.isEmpty()) {
+            super.visitEnd();
+            return;
+        }
+
+        boolean areAnyUncheckedMethods = false;
+
+        for (MethodDescription method : mMethodsToCheck) {
+            if (method.shouldCreateOverride == null) {
+                areAnyUncheckedMethods = true;
+                break;
+            }
+        }
+
+        if (areAnyUncheckedMethods) {
+            checkParentClass(mSuperName, mMethodsToCheck, mJarClassLoader);
+        }
+
+        super.visitEnd();
+    }
+
+    private boolean isClassView(String desc) {
+        Class currentClass = getClass(desc);
+        Class viewClass = getClass(VIEW_CLASS_DESCRIPTOR);
+        if (currentClass != null && viewClass != null) {
+            return viewClass.isAssignableFrom(currentClass);
+        }
+        return false;
+    }
+
+    private Class getClass(String desc) {
+        try {
+            return mJarClassLoader.loadClass(desc.replace('/', '.'));
+        } catch (ClassNotFoundException | NoClassDefFoundError | IllegalAccessError e) {
+            return null;
+        }
+    }
+
+    static void checkParentClass(String superClassName, ArrayList<MethodDescription> methodsToCheck,
+            ClassLoader jarClassLoader) {
+        try {
+            ClassReader cr = new ClassReader(getClassAsStream(jarClassLoader, superClassName));
+            ParentMethodCheckerClassAdapter parentChecker =
+                    new ParentMethodCheckerClassAdapter(methodsToCheck, jarClassLoader);
+            cr.accept(parentChecker, EXPAND_FRAMES);
+        } catch (IOException ex) {
+            // Ignore errors in case class can't be loaded.
+        }
+    }
+
+    private static InputStream getClassAsStream(ClassLoader jarClassLoader, String desc) {
+        return jarClassLoader.getResourceAsStream(desc.replace('.', '/') + ".class");
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/MethodDescription.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/MethodDescription.java
new file mode 100644
index 0000000000..23b14536e1
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/MethodDescription.java
@@ -0,0 +1,20 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+class MethodDescription {
+    public final String methodName;
+    public final String description;
+    public final int access;
+    public Boolean shouldCreateOverride;
+
+    public MethodDescription(String methodName, String description, int access) {
+        this.methodName = methodName;
+        this.description = description;
+        this.access = access;
+        // A null value means we haven't checked the method.
+        this.shouldCreateOverride = null;
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ParentMethodCheckerClassAdapter.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ParentMethodCheckerClassAdapter.java
new file mode 100644
index 0000000000..d913f1a73e
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/ParentMethodCheckerClassAdapter.java
@@ -0,0 +1,94 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import static org.objectweb.asm.Opcodes.ACC_FINAL;
+import static org.objectweb.asm.Opcodes.ACC_PRIVATE;
+import static org.objectweb.asm.Opcodes.ASM7;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+
+import java.util.ArrayList;
+
+/**
+ * This ClassVisitor checks if the given class overrides methods on {@code methodsToCheck}, and if
+ * so it determines whether they can be overridden by a child class. If at the end any unchecked
+ * methods remain then we recurse on the class's superclass.
+ */
+class ParentMethodCheckerClassAdapter extends ClassVisitor {
+    private static final String OBJECT_CLASS_DESCRIPTOR = "java.lang.Object";
+
+    private final ArrayList<MethodDescription> mMethodsToCheck;
+    private final ClassLoader mJarClassLoader;
+    private String mSuperName;
+    private boolean mIsCheckingObjectClass;
+
+    public ParentMethodCheckerClassAdapter(
+            ArrayList<MethodDescription> methodsToCheck, ClassLoader jarClassLoader) {
+        super(ASM7);
+        mMethodsToCheck = methodsToCheck;
+        mJarClassLoader = jarClassLoader;
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName,
+            String[] interfaces) {
+        super.visit(version, access, name, signature, superName, interfaces);
+
+        if (name.equals(OBJECT_CLASS_DESCRIPTOR)) {
+            mIsCheckingObjectClass = true;
+            return;
+        }
+
+        mSuperName = superName;
+    }
+
+    @Override
+    public MethodVisitor visitMethod(
+            int access, String name, String descriptor, String signature, String[] exceptions) {
+        if (mIsCheckingObjectClass) {
+            return super.visitMethod(access, name, descriptor, signature, exceptions);
+        }
+
+        for (MethodDescription methodToCheck : mMethodsToCheck) {
+            if (methodToCheck.shouldCreateOverride != null || !methodToCheck.methodName.equals(name)
+                    || !methodToCheck.description.equals(descriptor)) {
+                continue;
+            }
+
+            // This class contains methodToCheck.
+            boolean isMethodPrivate = (access & ACC_PRIVATE) == ACC_PRIVATE;
+            boolean isMethodFinal = (access & ACC_FINAL) == ACC_FINAL;
+            // If the method is private or final then don't create an override.
+            methodToCheck.shouldCreateOverride = !isMethodPrivate && !isMethodFinal;
+        }
+
+        return super.visitMethod(access, name, descriptor, signature, exceptions);
+    }
+
+    @Override
+    public void visitEnd() {
+        if (mIsCheckingObjectClass) {
+            return;
+        }
+
+        boolean areAnyUncheckedMethods = false;
+
+        for (MethodDescription method : mMethodsToCheck) {
+            if (method.shouldCreateOverride == null) {
+                areAnyUncheckedMethods = true;
+                break;
+            }
+        }
+
+        if (areAnyUncheckedMethods) {
+            MethodCheckerClassAdapter.checkParentClass(
+                    mSuperName, mMethodsToCheck, mJarClassLoader);
+        }
+
+        super.visitEnd();
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdder.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdder.java
new file mode 100644
index 0000000000..51f323f00a
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdder.java
@@ -0,0 +1,87 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.Opcodes;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+/**
+ * Java application that modifies all implementations of "draw", "onMeasure" and "onLayout" on all
+ * {@link android.view.View} subclasses to wrap them in trace events.
+ */
+public class TraceEventAdder extends ByteCodeRewriter {
+    private final ClassLoader mClassPathJarsClassLoader;
+    private ArrayList<MethodDescription> mMethodsToTrace;
+
+    public static void main(String[] args) throws IOException {
+        // Invoke this script using //build/android/gyp/bytecode_rewriter.py
+        if (args.length < 2) {
+            System.err.println(
+                    "Expected arguments: <input.jar> <output.jar> <input classpath jars>");
+            System.exit(1);
+        }
+
+        String input = args[0];
+        String output = args[1];
+
+        ArrayList<String> classPathJarsPaths = new ArrayList<>();
+        classPathJarsPaths.add(input);
+        classPathJarsPaths.addAll(Arrays.asList(Arrays.copyOfRange(args, 2, args.length)));
+        ClassLoader classPathJarsClassLoader = ByteCodeProcessor.loadJars(classPathJarsPaths);
+
+        TraceEventAdder adder = new TraceEventAdder(classPathJarsClassLoader);
+        adder.rewrite(new File(input), new File(output));
+    }
+
+    public TraceEventAdder(ClassLoader classPathJarsClassLoader) {
+        mClassPathJarsClassLoader = classPathJarsClassLoader;
+    }
+
+    @Override
+    protected boolean shouldRewriteClass(String classPath) {
+        try {
+            // If this jar's dependencies can't find Chromium's TraceEvent class then skip this
+            // class. Conceptually this could be fixed by adding a dependency on //base:base_java
+            // but that would cause circular dependencies and any changes to base_java would cause
+            // all android_library targets to require rebuilding.
+            mClassPathJarsClassLoader.loadClass("org.chromium.base.TraceEvent");
+            return true;
+        } catch (ClassNotFoundException ex) {
+            return false;
+        }
+    }
+
+    @Override
+    protected boolean shouldRewriteClass(ClassReader classReader) {
+        mMethodsToTrace = new ArrayList<>(Arrays.asList(
+                new MethodDescription("draw", "(Landroid/graphics/Canvas;)V", Opcodes.ACC_PUBLIC),
+                new MethodDescription("onMeasure", "(II)V", Opcodes.ACC_PROTECTED),
+                new MethodDescription("onLayout", "(ZIIII)V", Opcodes.ACC_PROTECTED)));
+
+        // This adapter will modify mMethodsToTrace to indicate which methods already exist in the
+        // class and which ones need to be overridden. In case the class is not an Android view
+        // we'll clear the list and skip rewriting.
+        MethodCheckerClassAdapter methodChecker =
+                new MethodCheckerClassAdapter(mMethodsToTrace, mClassPathJarsClassLoader);
+
+        classReader.accept(methodChecker, ClassReader.EXPAND_FRAMES);
+
+        return !mMethodsToTrace.isEmpty();
+    }
+
+    @Override
+    protected ClassVisitor getClassVisitorForClass(String classPath, ClassVisitor delegate) {
+        ClassVisitor chain = new TraceEventAdderClassAdapter(delegate, mMethodsToTrace);
+        chain = new EmptyOverrideGeneratorClassAdapter(chain, mMethodsToTrace);
+
+        return chain;
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdderClassAdapter.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdderClassAdapter.java
new file mode 100644
index 0000000000..c4a152d995
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdderClassAdapter.java
@@ -0,0 +1,47 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import static org.objectweb.asm.Opcodes.ASM7;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+
+import java.util.ArrayList;
+
+/**
+ * A ClassVisitor for adding TraceEvent.begin and TraceEvent.end methods to any methods specified in
+ * a list.
+ */
+class TraceEventAdderClassAdapter extends ClassVisitor {
+    private final ArrayList<MethodDescription> mMethodsToTrace;
+    private String mShortClassName;
+
+    TraceEventAdderClassAdapter(ClassVisitor visitor, ArrayList<MethodDescription> methodsToTrace) {
+        super(ASM7, visitor);
+        mMethodsToTrace = methodsToTrace;
+    }
+
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName,
+            String[] interfaces) {
+        super.visit(version, access, name, signature, superName, interfaces);
+        mShortClassName = name.substring(name.lastIndexOf('/') + 1);
+    }
+
+    @Override
+    public MethodVisitor visitMethod(final int access, final String name, String desc,
+            String signature, String[] exceptions) {
+        MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
+
+        for (MethodDescription method : mMethodsToTrace) {
+            if (method.methodName.equals(name) && method.description.equals(desc)) {
+                return new TraceEventAdderMethodAdapter(mv, mShortClassName, name);
+            }
+        }
+
+        return mv;
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdderMethodAdapter.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdderMethodAdapter.java
new file mode 100644
index 0000000000..042b3d3c5f
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TraceEventAdderMethodAdapter.java
@@ -0,0 +1,83 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import static org.objectweb.asm.Opcodes.ASM7;
+import static org.objectweb.asm.Opcodes.ATHROW;
+import static org.objectweb.asm.Opcodes.INVOKESTATIC;
+import static org.objectweb.asm.Opcodes.IRETURN;
+import static org.objectweb.asm.Opcodes.RETURN;
+
+import static org.chromium.bytecode.TypeUtils.STRING;
+import static org.chromium.bytecode.TypeUtils.VOID;
+
+import org.objectweb.asm.MethodVisitor;
+
+/**
+ * MethodVisitor that wraps all code in TraceEvent.begin and TraceEvent.end calls. TraceEvent.end
+ * calls are added on all returns and thrown exceptions.
+ *
+ * Example:
+ * <pre>
+ *   {@code
+ *      int methodToTrace(String foo){
+ *
+ *        //Line added by rewriter:
+ *        TraceEvent.begin("ClassName.methodToTrace");
+ *
+ *        if(foo == null){
+ *          //Line added by rewriter:
+ *          TraceEvent.end("ClassName.methodToTrace");
+ *
+ *          throw new Exception();
+ *        }
+ *        else if(foo.equals("Two")){
+ *          //Line added by rewriter:
+ *          TraceEvent.end("ClassName.methodToTrace");
+ *
+ *          return 2;
+ *        }
+ *
+ *        //Line added by rewriter:
+ *        TraceEvent.end("ClassName.methodToTrace");
+ *
+ *        return 0;
+ *      }
+ *   }
+ * </pre>
+ *
+ */
+class TraceEventAdderMethodAdapter extends MethodVisitor {
+    private static final String TRACE_EVENT_DESCRIPTOR = "org/chromium/base/TraceEvent";
+    private static final String TRACE_EVENT_SIGNATURE = TypeUtils.getMethodDescriptor(VOID, STRING);
+    private final String mEventName;
+
+    public TraceEventAdderMethodAdapter(
+            MethodVisitor methodVisitor, String shortClassName, String methodName) {
+        super(ASM7, methodVisitor);
+
+        mEventName = shortClassName + "." + methodName;
+    }
+
+    @Override
+    public void visitCode() {
+        super.visitCode();
+
+        mv.visitLdcInsn(mEventName);
+        mv.visitMethodInsn(
+                INVOKESTATIC, TRACE_EVENT_DESCRIPTOR, "begin", TRACE_EVENT_SIGNATURE, false);
+    }
+
+    @Override
+    public void visitInsn(int opcode) {
+        if ((opcode >= IRETURN && opcode <= RETURN) || opcode == ATHROW) {
+            mv.visitLdcInsn(mEventName);
+            mv.visitMethodInsn(
+                    INVOKESTATIC, TRACE_EVENT_DESCRIPTOR, "end", TRACE_EVENT_SIGNATURE, false);
+        }
+
+        mv.visitInsn(opcode);
+    }
+}
diff --git a/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TypeUtils.java b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TypeUtils.java
new file mode 100644
index 0000000000..ed2dc2dc24
--- /dev/null
+++ b/third_party/libwebrtc/build/android/bytecode/java/org/chromium/bytecode/TypeUtils.java
@@ -0,0 +1,87 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import org.objectweb.asm.Type;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Utility methods for accessing {@link Type}s Strings.
+ *
+ * Useful definitions to keep in mind when using this class:
+ * Internal name - The fully qualified name for a type with dots replaced by slashes. Not really
+ * relevant for primitive types.
+ * Type descriptor - Single letters for primitive types, "L" + internal name + ";" for class types.
+ *
+ * The methods in this class accept internal names or primitive type descriptors.
+ */
+class TypeUtils {
+    static final String ASSERTION_ERROR = "java/lang/AssertionError";
+    static final String ASSET_MANAGER = "android/content/res/AssetManager";
+    static final String BUILD_HOOKS = "org/chromium/build/BuildHooks";
+    static final String BUILD_HOOKS_ANDROID = "org/chromium/build/BuildHooksAndroid";
+    static final String CONFIGURATION = "android/content/res/Configuration";
+    static final String CONTEXT = "android/content/Context";
+    static final String CONTEXT_WRAPPER = "android/content/ContextWrapper";
+    static final String RESOURCES = "android/content/res/Resources";
+    static final String STRING = "java/lang/String";
+    static final String THEME = "android/content/res/Resources$Theme";
+
+    static final String BOOLEAN = "Z";
+    static final String INT = "I";
+    static final String VOID = "V";
+    private static final Map<String, Type> PRIMITIVE_DESCRIPTORS;
+    static {
+        PRIMITIVE_DESCRIPTORS = new HashMap<>();
+        PRIMITIVE_DESCRIPTORS.put(Type.BOOLEAN_TYPE.toString(), Type.BOOLEAN_TYPE);
+        PRIMITIVE_DESCRIPTORS.put(Type.INT_TYPE.toString(), Type.INT_TYPE);
+        PRIMITIVE_DESCRIPTORS.put(Type.VOID_TYPE.toString(), Type.VOID_TYPE);
+    }
+
+    /**
+     * Returns the full method signature with internal names.
+     *
+     * @param methodName Name of the method (ex. "getResources").
+     * @param returnType Internal name for the return type.
+     * @param argumentTypes List of internal names for argument types.
+     * @return String representation of the method signature.
+     */
+    static String getMethodSignature(
+            String methodName, String returnType, String... argumentTypes) {
+        return methodName + getMethodDescriptor(returnType, argumentTypes);
+    }
+
+    /**
+     * Builds a method descriptor suitable for use with {@link org.objectweb.asm.MethodVisitor}.
+     *
+     * @param returnType Internal name for the return type of the method (primitive or class).
+     * @param argumentTypes Internal names for the argument types (primitive or class).
+     * @return The generated method descriptor.
+     */
+    static String getMethodDescriptor(String returnType, String... argumentTypes) {
+        Type[] typedArguments = new Type[argumentTypes.length];
+        for (int i = 0; i < argumentTypes.length; ++i) {
+            // Argument list should be empty in this case, not V (void).
+            assert !Type.VOID_TYPE.toString().equals(argumentTypes[i]);
+            typedArguments[i] = convert(argumentTypes[i]);
+        }
+        return Type.getMethodDescriptor(convert(returnType), typedArguments);
+    }
+
+    /**
+     * Converts an internal name for a type to a {@link Type}.
+     *
+     * @param type Internal name for a type (primitive or class).
+     * @return The resulting Type.
+     */
+    private static Type convert(String type) {
+        if (PRIMITIVE_DESCRIPTORS.containsKey(type)) {
+            return PRIMITIVE_DESCRIPTORS.get(type);
+        }
+        return Type.getObjectType(type);
+    }
+}