Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

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

6 files changed, 917 insertions, 0 deletions

diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/BootstrapApplication.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/BootstrapApplication.java
new file mode 100644
index 0000000000..f7003f27ea
--- /dev/null
+++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/BootstrapApplication.java
@@ -0,0 +1,297 @@
+// Copyright 2015 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.incrementalinstall;
+
+import android.app.Application;
+import android.app.Instrumentation;
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.os.Bundle;
+import android.util.Log;
+
+import dalvik.system.DexFile;
+
+import java.io.File;
+import java.lang.ref.WeakReference;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * An Application that replaces itself with another Application (as defined in
+ * an AndroidManifext.xml meta-data tag). It loads the other application only
+ * after side-loading its .so and .dex files from /data/local/tmp.
+ *
+ * This class is highly dependent on the private implementation details of
+ * Android's ActivityThread.java. However, it has been tested to work with
+ * JellyBean through Marshmallow.
+ */
+public final class BootstrapApplication extends Application {
+    private static final String TAG = "incrementalinstall";
+    private static final String MANAGED_DIR_PREFIX = "/data/local/tmp/incremental-app-";
+    private static final String REAL_APP_META_DATA_NAME = "incremental-install-real-app";
+    private static final String REAL_INSTRUMENTATION_META_DATA_NAME0 =
+            "incremental-install-real-instrumentation-0";
+    private static final String REAL_INSTRUMENTATION_META_DATA_NAME1 =
+            "incremental-install-real-instrumentation-1";
+
+    private ClassLoaderPatcher mClassLoaderPatcher;
+    private Application mRealApplication;
+    private Instrumentation mOrigInstrumentation;
+    private Instrumentation mRealInstrumentation;
+    private Object mStashedProviderList;
+    private Object mActivityThread;
+    public static DexFile[] sIncrementalDexFiles; // Needed by junit test runner.
+
+    @Override
+    protected void attachBaseContext(Context context) {
+        super.attachBaseContext(context);
+        try {
+            mActivityThread = Reflect.invokeMethod(Class.forName("android.app.ActivityThread"),
+                    "currentActivityThread");
+            mClassLoaderPatcher = new ClassLoaderPatcher(context);
+
+            mOrigInstrumentation =
+                    (Instrumentation) Reflect.getField(mActivityThread, "mInstrumentation");
+            Context instContext = mOrigInstrumentation.getContext();
+            if (instContext == null) {
+                instContext = context;
+            }
+
+            // When running with an instrumentation that lives in a different package from the
+            // application, we must load the dex files and native libraries from both pacakges.
+            // This logic likely won't work when the instrumentation is incremental, but the app is
+            // non-incremental. This configuration isn't used right now though.
+            String appPackageName = getPackageName();
+            String instPackageName = instContext.getPackageName();
+            boolean instPackageNameDiffers = !appPackageName.equals(instPackageName);
+            Log.i(TAG, "App PackageName: " + appPackageName);
+            if (instPackageNameDiffers) {
+                Log.i(TAG, "Inst PackageName: " + instPackageName);
+            }
+
+            File appIncrementalRootDir = new File(MANAGED_DIR_PREFIX + appPackageName);
+            File appLibDir = new File(appIncrementalRootDir, "lib");
+            File appDexDir = new File(appIncrementalRootDir, "dex");
+            File appInstallLockFile = new File(appIncrementalRootDir, "install.lock");
+            File appFirstRunLockFile = new File(appIncrementalRootDir, "firstrun.lock");
+            File instIncrementalRootDir = new File(MANAGED_DIR_PREFIX + instPackageName);
+            File instLibDir = new File(instIncrementalRootDir, "lib");
+            File instDexDir = new File(instIncrementalRootDir, "dex");
+            File instInstallLockFile = new File(instIncrementalRootDir, "install.lock");
+            File instFirstRunLockFile = new File(instIncrementalRootDir, "firstrun.lock");
+
+            boolean isFirstRun = LockFile.installerLockExists(appFirstRunLockFile)
+                    || (instPackageNameDiffers
+                               && LockFile.installerLockExists(instFirstRunLockFile));
+            if (isFirstRun) {
+                if (mClassLoaderPatcher.mIsPrimaryProcess) {
+                    // Wait for incremental_install.py to finish.
+                    LockFile.waitForInstallerLock(appInstallLockFile, 30 * 1000);
+                    LockFile.waitForInstallerLock(instInstallLockFile, 30 * 1000);
+                } else {
+                    // Wait for the browser process to create the optimized dex files
+                    // and copy the library files.
+                    LockFile.waitForInstallerLock(appFirstRunLockFile, 60 * 1000);
+                    LockFile.waitForInstallerLock(instFirstRunLockFile, 60 * 1000);
+                }
+            }
+
+            mClassLoaderPatcher.importNativeLibs(instLibDir);
+            sIncrementalDexFiles = mClassLoaderPatcher.loadDexFiles(instDexDir, instPackageName);
+            if (instPackageNameDiffers) {
+                mClassLoaderPatcher.importNativeLibs(appLibDir);
+                mClassLoaderPatcher.loadDexFiles(appDexDir, appPackageName);
+            }
+
+            if (isFirstRun && mClassLoaderPatcher.mIsPrimaryProcess) {
+                LockFile.clearInstallerLock(appFirstRunLockFile);
+                if (instPackageNameDiffers) {
+                    LockFile.clearInstallerLock(instFirstRunLockFile);
+                }
+            }
+
+            // mInstrumentationAppDir is one of a set of fields that is initialized only when
+            // instrumentation is active.
+            if (Reflect.getField(mActivityThread, "mInstrumentationAppDir") != null) {
+                String metaDataName = REAL_INSTRUMENTATION_META_DATA_NAME0;
+                if (mOrigInstrumentation instanceof SecondInstrumentation) {
+                    metaDataName = REAL_INSTRUMENTATION_META_DATA_NAME1;
+                }
+                mRealInstrumentation =
+                        initInstrumentation(getClassNameFromMetadata(metaDataName, instContext));
+            } else {
+                Log.i(TAG, "No instrumentation active.");
+            }
+
+            // Even when instrumentation is not enabled, ActivityThread uses a default
+            // Instrumentation instance internally. We hook it here in order to hook into the
+            // call to Instrumentation.onCreate().
+            BootstrapInstrumentation bootstrapInstrumentation = new BootstrapInstrumentation(this);
+            populateInstrumenationFields(bootstrapInstrumentation);
+            Reflect.setField(mActivityThread, "mInstrumentation", bootstrapInstrumentation);
+
+            // attachBaseContext() is called from ActivityThread#handleBindApplication() and
+            // Application#mApplication is changed right after we return. Thus, we cannot swap
+            // the Application instances until onCreate() is called.
+            String realApplicationName = getClassNameFromMetadata(REAL_APP_META_DATA_NAME, context);
+            Log.i(TAG, "Instantiating " + realApplicationName);
+            Instrumentation anyInstrumentation =
+                    mRealInstrumentation != null ? mRealInstrumentation : mOrigInstrumentation;
+            mRealApplication = anyInstrumentation.newApplication(
+                    getClassLoader(), realApplicationName, context);
+
+            // Between attachBaseContext() and onCreate(), ActivityThread tries to instantiate
+            // all ContentProviders. The ContentProviders break without the correct Application
+            // class being installed, so temporarily pretend there are no providers, and then
+            // instantiate them explicitly within onCreate().
+            disableContentProviders();
+            Log.i(TAG, "Waiting for Instrumentation.onCreate");
+        } catch (Exception e) {
+            throw new RuntimeException("Incremental install failed.", e);
+        }
+    }
+
+    /**
+     * Returns the fully-qualified class name for the given key, stored in a
+     * <meta> witin the manifest.
+     */
+    private static String getClassNameFromMetadata(String key, Context context)
+            throws NameNotFoundException {
+        String pkgName = context.getPackageName();
+        ApplicationInfo appInfo = context.getPackageManager().getApplicationInfo(pkgName,
+                PackageManager.GET_META_DATA);
+        String value = appInfo.metaData.getString(key);
+        if (value != null && !value.contains(".")) {
+            value = pkgName + "." + value;
+        }
+        return value;
+    }
+
+    /**
+     * Instantiates and initializes mRealInstrumentation (the real Instrumentation class).
+     */
+    private Instrumentation initInstrumentation(String realInstrumentationName)
+            throws ReflectiveOperationException {
+        if (realInstrumentationName == null) {
+            // This is the case when an incremental app is used as a target for an instrumentation
+            // test. In this case, ActivityThread can instantiate the proper class just fine since
+            // it exists within the test apk (as opposed to the incremental apk-under-test).
+            Log.i(TAG, "Running with external instrumentation");
+            return null;
+        }
+        // For unit tests, the instrumentation class is replaced in the manifest by a build step
+        // because ActivityThread tries to instantiate it before we get a chance to load the
+        // incremental dex files.
+        Log.i(TAG, "Instantiating instrumentation " + realInstrumentationName);
+        Instrumentation ret =
+                (Instrumentation) Reflect.newInstance(Class.forName(realInstrumentationName));
+        populateInstrumenationFields(ret);
+        return ret;
+    }
+
+    /**
+     * Sets important fields on a newly created Instrumentation object by copying them from the
+     * original Instrumentation instance.
+     */
+    private void populateInstrumenationFields(Instrumentation target)
+            throws ReflectiveOperationException {
+        // Initialize the fields that are set by Instrumentation.init().
+        String[] initFields = {"mAppContext", "mComponent", "mInstrContext", "mMessageQueue",
+                "mThread", "mUiAutomationConnection", "mWatcher"};
+        for (String fieldName : initFields) {
+            Reflect.setField(target, fieldName, Reflect.getField(mOrigInstrumentation, fieldName));
+        }
+    }
+
+    /**
+     * Called by BootstrapInstrumentation from Instrumentation.onCreate().
+     * This happens regardless of whether or not instrumentation is enabled.
+     */
+    void onInstrumentationCreate(Bundle arguments) {
+        Log.i(TAG, "Instrumentation.onCreate() called. Swapping references.");
+        try {
+            swapApplicationReferences();
+            enableContentProviders();
+            if (mRealInstrumentation != null) {
+                Reflect.setField(mActivityThread, "mInstrumentation", mRealInstrumentation);
+                mRealInstrumentation.onCreate(arguments);
+            }
+        } catch (Exception e) {
+            throw new RuntimeException("Incremental install failed.", e);
+        }
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        try {
+            Log.i(TAG, "Application.onCreate() called.");
+            mRealApplication.onCreate();
+        } catch (Exception e) {
+            throw new RuntimeException("Incremental install failed.", e);
+        }
+    }
+
+    /**
+     * Nulls out ActivityThread.mBoundApplication.providers.
+     */
+    private void disableContentProviders() throws ReflectiveOperationException {
+        Object data = Reflect.getField(mActivityThread, "mBoundApplication");
+        mStashedProviderList = Reflect.getField(data, "providers");
+        Reflect.setField(data, "providers", null);
+    }
+
+    /**
+     * Restores the value of ActivityThread.mBoundApplication.providers, and invokes
+     * ActivityThread#installContentProviders().
+     */
+    private void enableContentProviders() throws ReflectiveOperationException {
+        Object data = Reflect.getField(mActivityThread, "mBoundApplication");
+        Reflect.setField(data, "providers", mStashedProviderList);
+        if (mStashedProviderList != null && mClassLoaderPatcher.mIsPrimaryProcess) {
+            Log.i(TAG, "Instantiating content providers");
+            Reflect.invokeMethod(mActivityThread, "installContentProviders", mRealApplication,
+                    mStashedProviderList);
+        }
+        mStashedProviderList = null;
+    }
+
+    /**
+     * Changes all fields within framework classes that have stored an reference to this
+     * BootstrapApplication to instead store references to mRealApplication.
+     */
+    @SuppressWarnings("unchecked")
+    private void swapApplicationReferences() throws ReflectiveOperationException {
+        if (Reflect.getField(mActivityThread, "mInitialApplication") == this) {
+            Reflect.setField(mActivityThread, "mInitialApplication", mRealApplication);
+        }
+
+        List<Application> allApplications =
+                (List<Application>) Reflect.getField(mActivityThread, "mAllApplications");
+        for (int i = 0; i < allApplications.size(); i++) {
+            if (allApplications.get(i) == this) {
+                allApplications.set(i, mRealApplication);
+            }
+        }
+
+        // Contains a reference to BootstrapApplication and will cause BroadCastReceivers to fail
+        // if not replaced.
+        Context contextImpl = mRealApplication.getBaseContext();
+        Reflect.setField(contextImpl, "mOuterContext", mRealApplication);
+
+        for (String fieldName : new String[] {"mPackages", "mResourcePackages"}) {
+            Map<String, WeakReference<?>> packageMap =
+                    (Map<String, WeakReference<?>>) Reflect.getField(mActivityThread, fieldName);
+            for (Map.Entry<String, WeakReference<?>> entry : packageMap.entrySet()) {
+                Object loadedApk = entry.getValue().get();
+                if (loadedApk != null && Reflect.getField(loadedApk, "mApplication") == this) {
+                    Reflect.setField(loadedApk, "mApplication", mRealApplication);
+                }
+            }
+        }
+    }
+}
diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/BootstrapInstrumentation.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/BootstrapInstrumentation.java
new file mode 100644
index 0000000000..f197406499
--- /dev/null
+++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/BootstrapInstrumentation.java
@@ -0,0 +1,25 @@
+// Copyright 2015 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.incrementalinstall;
+
+import android.app.Instrumentation;
+import android.os.Bundle;
+
+/**
+ * Notifies BootstrapApplication of the call to Instrumentation.onCreate().
+ */
+public final class BootstrapInstrumentation extends Instrumentation {
+    private final BootstrapApplication mApp;
+
+    BootstrapInstrumentation(BootstrapApplication app) {
+        mApp = app;
+    }
+
+    @Override
+    public void onCreate(Bundle arguments) {
+        super.onCreate(arguments);
+        mApp.onInstrumentationCreate(arguments);
+    }
+}
diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/ClassLoaderPatcher.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/ClassLoaderPatcher.java
new file mode 100644
index 0000000000..b6d752247b
--- /dev/null
+++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/ClassLoaderPatcher.java
@@ -0,0 +1,312 @@
+// Copyright 2015 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.incrementalinstall;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.os.Build;
+import android.os.Process;
+import android.util.Log;
+
+import dalvik.system.DexFile;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.List;
+import java.util.Locale;
+
+/**
+ * Provides the ability to add native libraries and .dex files to an existing class loader.
+ * Tested with Jellybean MR2 - Marshmellow.
+ */
+final class ClassLoaderPatcher {
+    private static final String TAG = "incrementalinstall";
+    private final File mAppFilesSubDir;
+    private final ClassLoader mClassLoader;
+    private final Object mLibcoreOs;
+    private final int mProcessUid;
+    final boolean mIsPrimaryProcess;
+
+    ClassLoaderPatcher(Context context) throws ReflectiveOperationException {
+        mAppFilesSubDir =
+                new File(context.getApplicationInfo().dataDir, "incremental-install-files");
+        mClassLoader = context.getClassLoader();
+        mLibcoreOs = Reflect.getField(Class.forName("libcore.io.Libcore"), "os");
+        mProcessUid = Process.myUid();
+        mIsPrimaryProcess = context.getApplicationInfo().uid == mProcessUid;
+        Log.i(TAG, "uid=" + mProcessUid + " (isPrimary=" + mIsPrimaryProcess + ")");
+    }
+
+    /**
+     * Loads all dex files within |dexDir| into the app's ClassLoader.
+     */
+    @SuppressLint({
+            "SetWorldReadable",
+            "SetWorldWritable",
+    })
+    DexFile[] loadDexFiles(File dexDir, String packageName)
+            throws ReflectiveOperationException, IOException {
+        Log.i(TAG, "Installing dex files from: " + dexDir);
+
+        File optimizedDir = null;
+        boolean isAtLeastOreo = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;
+
+        if (isAtLeastOreo) {
+            // In O, optimizedDirectory is ignored, and the files are always put in an "oat"
+            // directory that is a sibling to the dex files themselves. SELinux policies
+            // prevent using odex files from /data/local/tmp, so we must first copy them
+            // into the app's data directory in order to get the odex files to live there.
+            // Use a package-name subdirectory to prevent name collisions when apk-under-test is
+            // used.
+            File newDexDir = new File(mAppFilesSubDir, packageName + "-dexes");
+            if (mIsPrimaryProcess) {
+                safeCopyAllFiles(dexDir, newDexDir);
+            }
+            dexDir = newDexDir;
+        } else {
+            // The optimized dex files will be owned by this process' user.
+            // Store them within the app's data dir rather than on /data/local/tmp
+            // so that they are still deleted (by the OS) when we uninstall
+            // (even on a non-rooted device).
+            File incrementalDexesDir = new File(mAppFilesSubDir, "optimized-dexes");
+            File isolatedDexesDir = new File(mAppFilesSubDir, "isolated-dexes");
+
+            if (mIsPrimaryProcess) {
+                ensureAppFilesSubDirExists();
+                // Allows isolated processes to access the same files.
+                incrementalDexesDir.mkdir();
+                incrementalDexesDir.setReadable(true, false);
+                incrementalDexesDir.setExecutable(true, false);
+                // Create a directory for isolated processes to create directories in.
+                isolatedDexesDir.mkdir();
+                isolatedDexesDir.setWritable(true, false);
+                isolatedDexesDir.setExecutable(true, false);
+
+                optimizedDir = incrementalDexesDir;
+            } else {
+                // There is a UID check of the directory in dalvik.system.DexFile():
+                // https://android.googlesource.com/platform/libcore/+/45e0260/dalvik/src/main/java/dalvik/system/DexFile.java#101
+                // Rather than have each isolated process run DexOpt though, we use
+                // symlinks within the directory to point at the browser process'
+                // optimized dex files.
+                optimizedDir = new File(isolatedDexesDir, "isolated-" + mProcessUid);
+                optimizedDir.mkdir();
+                // Always wipe it out and re-create for simplicity.
+                Log.i(TAG, "Creating dex file symlinks for isolated process");
+                for (File f : optimizedDir.listFiles()) {
+                    f.delete();
+                }
+                for (File f : incrementalDexesDir.listFiles()) {
+                    String to = "../../" + incrementalDexesDir.getName() + "/" + f.getName();
+                    File from = new File(optimizedDir, f.getName());
+                    createSymlink(to, from);
+                }
+            }
+            Log.i(TAG, "Code cache dir: " + optimizedDir);
+        }
+
+        // Ignore "oat" directory.
+        // Also ignore files that sometimes show up (e.g. .jar.arm.flock).
+        File[] dexFilesArr = dexDir.listFiles(f -> f.getName().endsWith(".jar"));
+        if (dexFilesArr == null) {
+            throw new FileNotFoundException("Dex dir does not exist: " + dexDir);
+        }
+
+        Log.i(TAG, "Loading " + dexFilesArr.length + " dex files");
+
+        Object dexPathList = Reflect.getField(mClassLoader, "pathList");
+        Object[] dexElements = (Object[]) Reflect.getField(dexPathList, "dexElements");
+        dexElements = addDexElements(dexFilesArr, optimizedDir, dexElements);
+        Reflect.setField(dexPathList, "dexElements", dexElements);
+
+        // Return the list of new DexFile instances for the .jars in dexPathList.
+        DexFile[] ret = new DexFile[dexFilesArr.length];
+        int startIndex = dexElements.length - dexFilesArr.length;
+        for (int i = 0; i < ret.length; ++i) {
+            ret[i] = (DexFile) Reflect.getField(dexElements[startIndex + i], "dexFile");
+        }
+        return ret;
+    }
+
+    /**
+     * Sets up all libraries within |libDir| to be loadable by System.loadLibrary().
+     */
+    @SuppressLint("SetWorldReadable")
+    void importNativeLibs(File libDir) throws ReflectiveOperationException, IOException {
+        Log.i(TAG, "Importing native libraries from: " + libDir);
+        if (!libDir.exists()) {
+            Log.i(TAG, "No native libs exist.");
+            return;
+        }
+        // The library copying is not necessary on older devices, but we do it anyways to
+        // simplify things (it's fast compared to dexing).
+        // https://code.google.com/p/android/issues/detail?id=79480
+        File localLibsDir = new File(mAppFilesSubDir, "lib");
+        safeCopyAllFiles(libDir, localLibsDir);
+        addNativeLibrarySearchPath(localLibsDir);
+    }
+
+    @SuppressLint("SetWorldReadable")
+    private void safeCopyAllFiles(File srcDir, File dstDir) throws IOException {
+        // The library copying is not necessary on older devices, but we do it anyways to
+        // simplify things (it's fast compared to dexing).
+        // https://code.google.com/p/android/issues/detail?id=79480
+        File lockFile = new File(mAppFilesSubDir, dstDir.getName() + ".lock");
+        if (mIsPrimaryProcess) {
+            ensureAppFilesSubDirExists();
+            LockFile lock = LockFile.acquireRuntimeLock(lockFile);
+            if (lock == null) {
+                LockFile.waitForRuntimeLock(lockFile, 10 * 1000);
+            } else {
+                try {
+                    dstDir.mkdir();
+                    dstDir.setReadable(true, false);
+                    dstDir.setExecutable(true, false);
+                    copyChangedFiles(srcDir, dstDir);
+                } finally {
+                    lock.release();
+                }
+            }
+        } else {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                // TODO: Work around this issue by using APK splits to install each dex / lib.
+                throw new RuntimeException("Incremental install does not work on Android M+ "
+                        + "with isolated processes. Build system should have removed this. "
+                        + "Please file a bug.");
+            }
+            // Other processes: Waits for primary process to finish copying.
+            LockFile.waitForRuntimeLock(lockFile, 10 * 1000);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private void addNativeLibrarySearchPath(File nativeLibDir) throws ReflectiveOperationException {
+        Object dexPathList = Reflect.getField(mClassLoader, "pathList");
+        Object currentDirs = Reflect.getField(dexPathList, "nativeLibraryDirectories");
+        File[] newDirs = new File[] { nativeLibDir };
+        // Switched from an array to an ArrayList in Lollipop.
+        if (currentDirs instanceof List) {
+            List<File> dirsAsList = (List<File>) currentDirs;
+            dirsAsList.add(0, nativeLibDir);
+        } else {
+            File[] dirsAsArray = (File[]) currentDirs;
+            Reflect.setField(dexPathList, "nativeLibraryDirectories",
+                    Reflect.concatArrays(newDirs, newDirs, dirsAsArray));
+        }
+
+        Object[] nativeLibraryPathElements;
+        try {
+            nativeLibraryPathElements =
+                    (Object[]) Reflect.getField(dexPathList, "nativeLibraryPathElements");
+        } catch (NoSuchFieldException e) {
+            // This field doesn't exist pre-M.
+            return;
+        }
+        Object[] additionalElements = makeNativePathElements(newDirs);
+        Reflect.setField(dexPathList, "nativeLibraryPathElements",
+                Reflect.concatArrays(nativeLibraryPathElements, additionalElements,
+                        nativeLibraryPathElements));
+    }
+
+    private static void copyChangedFiles(File srcDir, File dstDir) throws IOException {
+        int numUpdated = 0;
+        File[] srcFiles = srcDir.listFiles();
+        for (File f : srcFiles) {
+            // Note: Tried using hardlinks, but resulted in EACCES exceptions.
+            File dest = new File(dstDir, f.getName());
+            if (copyIfModified(f, dest)) {
+                numUpdated++;
+            }
+        }
+        // Delete stale files.
+        int numDeleted = 0;
+        for (File f : dstDir.listFiles()) {
+            File src = new File(srcDir, f.getName());
+            if (!src.exists()) {
+                numDeleted++;
+                f.delete();
+            }
+        }
+        String msg = String.format(Locale.US,
+                "copyChangedFiles: %d of %d updated. %d stale files removed.", numUpdated,
+                srcFiles.length, numDeleted);
+        Log.i(TAG, msg);
+    }
+
+    @SuppressLint("SetWorldReadable")
+    private static boolean copyIfModified(File src, File dest) throws IOException {
+        long lastModified = src.lastModified();
+        if (dest.exists() && dest.lastModified() == lastModified) {
+            return false;
+        }
+        Log.i(TAG, "Copying " + src + " -> " + dest);
+        FileInputStream istream = new FileInputStream(src);
+        FileOutputStream ostream = new FileOutputStream(dest);
+        ostream.getChannel().transferFrom(istream.getChannel(), 0, istream.getChannel().size());
+        istream.close();
+        ostream.close();
+        dest.setReadable(true, false);
+        dest.setExecutable(true,  false);
+        dest.setLastModified(lastModified);
+        return true;
+    }
+
+    private void ensureAppFilesSubDirExists() {
+        mAppFilesSubDir.mkdir();
+        mAppFilesSubDir.setExecutable(true, false);
+    }
+
+    private void createSymlink(String to, File from) throws ReflectiveOperationException {
+        Reflect.invokeMethod(mLibcoreOs, "symlink", to, from.getAbsolutePath());
+    }
+
+    private static Object[] makeNativePathElements(File[] paths)
+            throws ReflectiveOperationException {
+        Object[] entries = new Object[paths.length];
+        if (Build.VERSION.SDK_INT >= 26) {
+            Class<?> entryClazz = Class.forName("dalvik.system.DexPathList$NativeLibraryElement");
+            for (int i = 0; i < paths.length; ++i) {
+                entries[i] = Reflect.newInstance(entryClazz, paths[i]);
+            }
+        } else {
+            Class<?> entryClazz = Class.forName("dalvik.system.DexPathList$Element");
+            for (int i = 0; i < paths.length; ++i) {
+                entries[i] = Reflect.newInstance(entryClazz, paths[i], true, null, null);
+            }
+        }
+        return entries;
+    }
+
+    private Object[] addDexElements(File[] files, File optimizedDirectory, Object[] curDexElements)
+            throws ReflectiveOperationException {
+        Class<?> entryClazz = Class.forName("dalvik.system.DexPathList$Element");
+        Class<?> clazz = Class.forName("dalvik.system.DexPathList");
+        Object[] ret =
+                Reflect.concatArrays(curDexElements, curDexElements, new Object[files.length]);
+        File emptyDir = new File("");
+        for (int i = 0; i < files.length; ++i) {
+            File file = files[i];
+            Object dexFile;
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+                // loadDexFile requires that ret contain all previously added elements.
+                dexFile = Reflect.invokeMethod(clazz, "loadDexFile", file, optimizedDirectory,
+                                               mClassLoader, ret);
+            } else {
+                dexFile = Reflect.invokeMethod(clazz, "loadDexFile", file, optimizedDirectory);
+            }
+            Object dexElement;
+            if (Build.VERSION.SDK_INT >= 26) {
+                dexElement = Reflect.newInstance(entryClazz, dexFile, file);
+            } else {
+                dexElement = Reflect.newInstance(entryClazz, emptyDir, false, file, dexFile);
+            }
+            ret[curDexElements.length + i] = dexElement;
+        }
+        return ret;
+    }
+}
diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java
new file mode 100644
index 0000000000..19d1f7624e
--- /dev/null
+++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java
@@ -0,0 +1,129 @@
+// Copyright 2015 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.incrementalinstall;
+
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.channels.FileLock;
+import java.util.concurrent.Callable;
+
+/**
+ * Helpers for dealing with .lock files used during install / first run.
+ */
+final class LockFile {
+    private static final String TAG = "incrementalinstall";
+
+    private final File mFile;
+    private final FileOutputStream mOutputStream;
+    private final FileLock mFileLock;
+
+    private LockFile(File file, FileOutputStream outputStream, FileLock fileLock) {
+        mFile = file;
+        mOutputStream = outputStream;
+        mFileLock = fileLock;
+    }
+
+    /**
+     * Clears the lock file by writing to it (making it non-zero in length);
+     */
+    static void clearInstallerLock(File lockFile) throws IOException {
+        Log.i(TAG, "Clearing " + lockFile);
+        // On Android M+, we can't delete files in /data/local/tmp, so we write to it instead.
+        FileOutputStream os = new FileOutputStream(lockFile);
+        os.write(1);
+        os.close();
+    }
+
+    /**
+     * Waits for the given file to be non-zero in length.
+     */
+    static void waitForInstallerLock(final File file, long timeoutMs) {
+        pollingWait(new Callable<Boolean>() {
+            @Override public Boolean call() {
+                return !installerLockExists(file);
+            }
+        }, file, timeoutMs);
+    }
+
+    /**
+     * Waits for the given file to be non-zero in length.
+     */
+    private static void pollingWait(Callable<Boolean> func, File file, long timeoutMs) {
+        long pollIntervalMs = 200;
+        for (int i = 0; i < timeoutMs / pollIntervalMs; i++) {
+            try {
+                if (func.call()) {
+                    if (i > 0) {
+                        Log.i(TAG, "Finished waiting on lock file: " + file);
+                    }
+                    return;
+                } else if (i == 0) {
+                    Log.i(TAG, "Waiting on lock file: " + file);
+                }
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+            try {
+                Thread.sleep(pollIntervalMs);
+            } catch (InterruptedException e) {
+                // Should never happen.
+            }
+        }
+        throw new RuntimeException("Timed out waiting for lock file: " + file);
+    }
+
+    /**
+     * Returns whether the given lock file is missing or is in the locked state.
+     */
+    static boolean installerLockExists(File file) {
+        return !file.exists() || file.length() == 0;
+    }
+
+    /**
+     * Attempts to acquire a lock for the given file.
+     * @return Returns the FileLock if it was acquired, or null otherwise.
+     */
+    static LockFile acquireRuntimeLock(File file) {
+        try {
+            FileOutputStream outputStream = new FileOutputStream(file);
+            FileLock lock = outputStream.getChannel().tryLock();
+            if (lock != null) {
+                Log.i(TAG, "Created lock file: " + file);
+                return new LockFile(file, outputStream, lock);
+            }
+            outputStream.close();
+        } catch (IOException e) {
+            // Do nothing. We didn't get the lock.
+            Log.w(TAG, "Exception trying to acquire lock " + file, e);
+        }
+        return null;
+    }
+
+    /**
+     * Waits for the given file to not exist.
+     */
+    static void waitForRuntimeLock(final File file, long timeoutMs) {
+        pollingWait(new Callable<Boolean>() {
+            @Override public Boolean call() {
+                return !file.exists();
+            }
+        }, file, timeoutMs);
+    }
+
+    /**
+     * Releases and deletes the lock file.
+     */
+    void release() throws IOException {
+        Log.i(TAG, "Deleting lock file: " + mFile);
+        mFileLock.release();
+        mOutputStream.close();
+        if (!mFile.delete()) {
+            throw new IOException("Failed to delete lock file: " + mFile);
+        }
+    }
+}
diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/Reflect.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/Reflect.java
new file mode 100644
index 0000000000..c64dc1e8a3
--- /dev/null
+++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/Reflect.java
@@ -0,0 +1,142 @@
+// Copyright 2015 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.incrementalinstall;
+
+import java.lang.reflect.Array;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+
+/**
+ * Reflection helper methods.
+ */
+final class Reflect {
+    /**
+     * Sets the value of an object's field (even if it's not visible).
+     *
+     * @param instance The object containing the field to set.
+     * @param name The name of the field to set.
+     * @param value The new value for the field.
+     */
+    static void setField(Object instance, String name, Object value)
+            throws ReflectiveOperationException {
+        Field field = findField(instance, name);
+        field.setAccessible(true);
+        field.set(instance, value);
+    }
+
+    /**
+     * Retrieves the value of an object's field (even if it's not visible).
+     *
+     * @param instance The object containing the field to set.
+     * @param name The name of the field to set.
+     * @return The field's value. Primitive values are returned as their boxed
+     *         type.
+     */
+    static Object getField(Object instance, String name) throws ReflectiveOperationException {
+        Field field = findField(instance, name);
+        field.setAccessible(true);
+        return field.get(instance);
+    }
+
+    /**
+     * Concatenates two arrays into a new array. The arrays must be of the same
+     * type.
+     */
+    static Object[] concatArrays(Object[] arrType, Object[] left, Object[] right) {
+        Object[] result = (Object[]) Array.newInstance(
+                arrType.getClass().getComponentType(), left.length + right.length);
+        System.arraycopy(left, 0, result, 0, left.length);
+        System.arraycopy(right, 0, result, left.length, right.length);
+        return result;
+    }
+
+    /**
+     * Invokes a method with zero or more parameters. For static methods, use the Class as the
+     * instance.
+     */
+    static Object invokeMethod(Object instance, String name, Object... params)
+            throws ReflectiveOperationException {
+        boolean isStatic = instance instanceof Class;
+        Class<?> clazz = isStatic ? (Class<?>) instance :  instance.getClass();
+        Method method = findMethod(clazz, name, params);
+        method.setAccessible(true);
+        return method.invoke(instance, params);
+    }
+
+    /**
+     * Calls a constructor with zero or more parameters.
+     */
+    static Object newInstance(Class<?> clazz, Object... params)
+            throws ReflectiveOperationException {
+        Constructor<?> constructor = findConstructor(clazz, params);
+        constructor.setAccessible(true);
+        return constructor.newInstance(params);
+    }
+
+    private static Field findField(Object instance, String name) throws NoSuchFieldException {
+        boolean isStatic = instance instanceof Class;
+        Class<?> clazz = isStatic ? (Class<?>) instance :  instance.getClass();
+        for (; clazz != null; clazz = clazz.getSuperclass()) {
+            try {
+                return clazz.getDeclaredField(name);
+            } catch (NoSuchFieldException e) {
+                // Need to look in the super class.
+            }
+        }
+        throw new NoSuchFieldException("Field " + name + " not found in " + instance.getClass());
+    }
+
+    private static Method findMethod(Class<?> clazz, String name, Object... params)
+            throws NoSuchMethodException {
+        for (; clazz != null; clazz = clazz.getSuperclass()) {
+            for (Method method : clazz.getDeclaredMethods()) {
+                if (method.getName().equals(name)
+                        && areParametersCompatible(method.getParameterTypes(), params)) {
+                    return method;
+                }
+            }
+        }
+        throw new NoSuchMethodException("Method " + name + " with parameters "
+                + Arrays.asList(params) + " not found in " + clazz);
+    }
+
+    private static Constructor<?> findConstructor(Class<?> clazz, Object... params)
+            throws NoSuchMethodException {
+        for (Constructor<?> constructor : clazz.getDeclaredConstructors()) {
+            if (areParametersCompatible(constructor.getParameterTypes(), params)) {
+                return constructor;
+            }
+        }
+        throw new NoSuchMethodException("Constructor with parameters " + Arrays.asList(params)
+                + " not found in " + clazz);
+    }
+
+    private static boolean areParametersCompatible(Class<?>[] paramTypes, Object... params) {
+        if (params.length != paramTypes.length) {
+            return false;
+        }
+        for (int i = 0; i < params.length; i++) {
+            if (!isAssignableFrom(paramTypes[i], params[i])) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static boolean isAssignableFrom(Class<?> left, Object right) {
+        if (right == null) {
+            return !left.isPrimitive();
+        }
+        Class<?> rightClazz = right.getClass();
+        if (left.isPrimitive()) {
+            // TODO(agrieve): Fill in the rest as needed.
+            return left == boolean.class && rightClazz == Boolean.class
+                   || left == int.class && rightClazz == Integer.class;
+        }
+        return left.isAssignableFrom(rightClazz);
+    }
+}
diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/SecondInstrumentation.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/SecondInstrumentation.java
new file mode 100644
index 0000000000..3e0df0521e
--- /dev/null
+++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/SecondInstrumentation.java
@@ -0,0 +1,12 @@
+// 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.incrementalinstall;
+
+import android.app.Instrumentation;
+
+/**
+ * Exists to support an app having multiple instrumentations.
+ */
+public final class SecondInstrumentation extends Instrumentation {}