Adding upstream version 110.0.1.upstream/110.0.1upstream

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

1 files changed, 1725 insertions, 0 deletions

diff --git a/gfx/layers/opengl/CompositorOGL.cpp b/gfx/layers/opengl/CompositorOGL.cpp
new file mode 100644
index 0000000000..4cafbea88a
--- /dev/null
+++ b/gfx/layers/opengl/CompositorOGL.cpp
@@ -0,0 +1,1725 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CompositorOGL.h"
+#include <stddef.h>             // for size_t
+#include <stdint.h>             // for uint32_t, uint8_t
+#include <stdlib.h>             // for free, malloc
+#include "GLContextProvider.h"  // for GLContextProvider
+#include "GLContext.h"          // for GLContext
+#include "GLUploadHelpers.h"
+#include "gfxCrashReporterUtils.h"  // for ScopedGfxFeatureReporter
+#include "gfxEnv.h"                 // for gfxEnv
+#include "gfxPlatform.h"            // for gfxPlatform
+#include "gfxRect.h"                // for gfxRect
+#include "gfxUtils.h"               // for gfxUtils, etc
+#include "mozilla/ArrayUtils.h"     // for ArrayLength
+#include "mozilla/Preferences.h"    // for Preferences
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/StaticPrefs_gfx.h"
+#include "mozilla/StaticPrefs_layers.h"
+#include "mozilla/StaticPrefs_nglayout.h"
+#include "mozilla/gfx/BasePoint.h"  // for BasePoint
+#include "mozilla/gfx/Matrix.h"     // for Matrix4x4, Matrix
+#include "mozilla/gfx/Triangle.h"   // for Triangle
+#include "mozilla/gfx/gfxVars.h"    // for gfxVars
+#include "mozilla/layers/ImageDataSerializer.h"
+#include "mozilla/layers/NativeLayer.h"
+#include "mozilla/layers/CompositingRenderTargetOGL.h"
+#include "mozilla/layers/Effects.h"      // for EffectChain, TexturedEffect, etc
+#include "mozilla/layers/TextureHost.h"  // for TextureSource, etc
+#include "mozilla/layers/TextureHostOGL.h"  // for TextureSourceOGL, etc
+#include "mozilla/layers/PTextureParent.h"  // for OtherPid() on PTextureParent
+#include "mozilla/mozalloc.h"               // for operator delete, etc
+#include "nsAppRunner.h"
+#include "nsAString.h"
+#include "nsClassHashtable.h"
+#include "nsIConsoleService.h"      // for nsIConsoleService, etc
+#include "nsIWidget.h"              // for nsIWidget
+#include "nsLiteralString.h"        // for NS_LITERAL_STRING
+#include "nsMathUtils.h"            // for NS_roundf
+#include "nsRect.h"                 // for mozilla::gfx::IntRect
+#include "nsServiceManagerUtils.h"  // for do_GetService
+#include "nsString.h"               // for nsString, nsAutoCString, etc
+#include "OGLShaderProgram.h"       // for ShaderProgramOGL, etc
+#include "ScopedGLHelpers.h"
+#include "GLReadTexImageHelper.h"
+#include "HeapCopyOfStackArray.h"
+#include "GLBlitHelper.h"
+#include "mozilla/gfx/Swizzle.h"
+#ifdef MOZ_WAYLAND
+#  include "mozilla/widget/GtkCompositorWidget.h"
+#endif
+#if MOZ_WIDGET_ANDROID
+#  include "GLContextEGL.h"
+#  include "GLLibraryEGL.h"
+#  include "mozilla/java/GeckoSurfaceTextureWrappers.h"
+#  include "mozilla/layers/AndroidHardwareBuffer.h"
+#endif
+
+namespace mozilla {
+
+using namespace gfx;
+
+namespace layers {
+
+using namespace mozilla::gl;
+
+static const GLuint kCoordinateAttributeIndex = 0;
+static const GLuint kTexCoordinateAttributeIndex = 1;
+
+class AsyncReadbackBufferOGL final : public AsyncReadbackBuffer {
+ public:
+  AsyncReadbackBufferOGL(GLContext* aGL, const IntSize& aSize);
+
+  bool MapAndCopyInto(DataSourceSurface* aSurface,
+                      const IntSize& aReadSize) const override;
+
+  void Bind() const {
+    mGL->fBindBuffer(LOCAL_GL_PIXEL_PACK_BUFFER, mBufferHandle);
+    mGL->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, 1);
+  }
+
+ protected:
+  virtual ~AsyncReadbackBufferOGL();
+
+ private:
+  GLContext* mGL;
+  GLuint mBufferHandle;
+};
+
+AsyncReadbackBufferOGL::AsyncReadbackBufferOGL(GLContext* aGL,
+                                               const IntSize& aSize)
+    : AsyncReadbackBuffer(aSize), mGL(aGL), mBufferHandle(0) {
+  size_t bufferByteCount = mSize.width * mSize.height * 4;
+  mGL->fGenBuffers(1, &mBufferHandle);
+
+  ScopedPackState scopedPackState(mGL);
+  Bind();
+  mGL->fBufferData(LOCAL_GL_PIXEL_PACK_BUFFER, bufferByteCount, nullptr,
+                   LOCAL_GL_STREAM_READ);
+}
+
+AsyncReadbackBufferOGL::~AsyncReadbackBufferOGL() {
+  if (mGL && mGL->MakeCurrent()) {
+    mGL->fDeleteBuffers(1, &mBufferHandle);
+  }
+}
+
+bool AsyncReadbackBufferOGL::MapAndCopyInto(DataSourceSurface* aSurface,
+                                            const IntSize& aReadSize) const {
+  MOZ_RELEASE_ASSERT(aReadSize <= aSurface->GetSize());
+
+  if (!mGL || !mGL->MakeCurrent()) {
+    return false;
+  }
+
+  ScopedPackState scopedPackState(mGL);
+  Bind();
+
+  const uint8_t* srcData = nullptr;
+  if (mGL->IsSupported(GLFeature::map_buffer_range)) {
+    srcData = static_cast<uint8_t*>(mGL->fMapBufferRange(
+        LOCAL_GL_PIXEL_PACK_BUFFER, 0, aReadSize.height * aReadSize.width * 4,
+        LOCAL_GL_MAP_READ_BIT));
+  } else {
+    srcData = static_cast<uint8_t*>(
+        mGL->fMapBuffer(LOCAL_GL_PIXEL_PACK_BUFFER, LOCAL_GL_READ_ONLY));
+  }
+
+  if (!srcData) {
+    return false;
+  }
+
+  int32_t srcStride = mSize.width * 4;  // Bind() sets an alignment of 1
+  DataSourceSurface::ScopedMap map(aSurface, DataSourceSurface::WRITE);
+  uint8_t* destData = map.GetData();
+  int32_t destStride = map.GetStride();
+  SurfaceFormat destFormat = aSurface->GetFormat();
+  for (int32_t destRow = 0; destRow < aReadSize.height; destRow++) {
+    // Turn srcData upside down during the copy.
+    int32_t srcRow = aReadSize.height - 1 - destRow;
+    const uint8_t* src = &srcData[srcRow * srcStride];
+    uint8_t* dest = &destData[destRow * destStride];
+    SwizzleData(src, srcStride, SurfaceFormat::R8G8B8A8, dest, destStride,
+                destFormat, IntSize(aReadSize.width, 1));
+  }
+
+  mGL->fUnmapBuffer(LOCAL_GL_PIXEL_PACK_BUFFER);
+
+  return true;
+}
+
+PerUnitTexturePoolOGL::PerUnitTexturePoolOGL(gl::GLContext* aGL)
+    : mTextureTarget(0),  // zero is never a valid texture target
+      mGL(aGL) {}
+
+PerUnitTexturePoolOGL::~PerUnitTexturePoolOGL() { DestroyTextures(); }
+
+CompositorOGL::CompositorOGL(widget::CompositorWidget* aWidget,
+                             int aSurfaceWidth, int aSurfaceHeight,
+                             bool aUseExternalSurfaceSize)
+    : Compositor(aWidget),
+      mWidgetSize(-1, -1),
+      mSurfaceSize(aSurfaceWidth, aSurfaceHeight),
+      mFBOTextureTarget(0),
+      mWindowRenderTarget(nullptr),
+      mQuadVBO(0),
+      mTriangleVBO(0),
+      mPreviousFrameDoneSync(nullptr),
+      mThisFrameDoneSync(nullptr),
+      mHasBGRA(0),
+      mUseExternalSurfaceSize(aUseExternalSurfaceSize),
+      mFrameInProgress(false),
+      mDestroyed(false),
+      mViewportSize(0, 0) {
+  if (aWidget->GetNativeLayerRoot()) {
+    // We can only render into native layers, our GLContext won't have a usable
+    // default framebuffer.
+    mCanRenderToDefaultFramebuffer = false;
+  }
+  MOZ_COUNT_CTOR(CompositorOGL);
+}
+
+CompositorOGL::~CompositorOGL() { MOZ_COUNT_DTOR(CompositorOGL); }
+
+already_AddRefed<mozilla::gl::GLContext> CompositorOGL::CreateContext() {
+  RefPtr<GLContext> context;
+
+  // Used by mock widget to create an offscreen context
+  nsIWidget* widget = mWidget->RealWidget();
+  void* widgetOpenGLContext =
+      widget ? widget->GetNativeData(NS_NATIVE_OPENGL_CONTEXT) : nullptr;
+  if (widgetOpenGLContext) {
+    GLContext* alreadyRefed = reinterpret_cast<GLContext*>(widgetOpenGLContext);
+    return already_AddRefed<GLContext>(alreadyRefed);
+  }
+
+#ifdef XP_WIN
+  if (gfxEnv::MOZ_LAYERS_PREFER_EGL()) {
+    printf_stderr("Trying GL layers...\n");
+    context = gl::GLContextProviderEGL::CreateForCompositorWidget(
+        mWidget, /* aHardwareWebRender */ false, /* aForceAccelerated */ false);
+  }
+#endif
+
+  // Allow to create offscreen GL context for main Layer Manager
+  if (!context && gfxEnv::MOZ_LAYERS_PREFER_OFFSCREEN()) {
+    nsCString discardFailureId;
+    context = GLContextProvider::CreateHeadless(
+        {CreateContextFlags::REQUIRE_COMPAT_PROFILE}, &discardFailureId);
+    if (!context->CreateOffscreenDefaultFb(mSurfaceSize)) {
+      context = nullptr;
+    }
+  }
+
+  if (!context) {
+    context = gl::GLContextProvider::CreateForCompositorWidget(
+        mWidget,
+        /* aHardwareWebRender */ false,
+        gfxVars::RequiresAcceleratedGLContextForCompositorOGL());
+  }
+
+  if (!context) {
+    NS_WARNING("Failed to create CompositorOGL context");
+  }
+
+  return context.forget();
+}
+
+void CompositorOGL::Destroy() {
+  Compositor::Destroy();
+
+  if (mTexturePool) {
+    mTexturePool->Clear();
+    mTexturePool = nullptr;
+  }
+
+  if (!mDestroyed) {
+    mDestroyed = true;
+    CleanupResources();
+  }
+}
+
+void CompositorOGL::CleanupResources() {
+  if (!mGLContext) return;
+
+  if (mSurfacePoolHandle) {
+    mSurfacePoolHandle->Pool()->DestroyGLResourcesForContext(mGLContext);
+    mSurfacePoolHandle = nullptr;
+  }
+
+  RefPtr<GLContext> ctx = mGLContext->GetSharedContext();
+  if (!ctx) {
+    ctx = mGLContext;
+  }
+
+  if (!ctx->MakeCurrent()) {
+    // Leak resources!
+    mQuadVBO = 0;
+    mTriangleVBO = 0;
+    mPreviousFrameDoneSync = nullptr;
+    mThisFrameDoneSync = nullptr;
+    mProgramsHolder = nullptr;
+    mGLContext = nullptr;
+    mNativeLayersReferenceRT = nullptr;
+    mFullWindowRenderTarget = nullptr;
+    return;
+  }
+
+  mProgramsHolder = nullptr;
+  mNativeLayersReferenceRT = nullptr;
+  mFullWindowRenderTarget = nullptr;
+
+#ifdef MOZ_WIDGET_GTK
+  // TextureSources might hold RefPtr<gl::GLContext>.
+  // All of them needs to be released to destroy GLContext.
+  // GLContextGLX has to be destroyed before related gtk window is destroyed.
+  for (auto textureSource : mRegisteredTextureSources) {
+    textureSource->DeallocateDeviceData();
+  }
+  mRegisteredTextureSources.clear();
+#endif
+
+  ctx->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, 0);
+
+  if (mQuadVBO) {
+    ctx->fDeleteBuffers(1, &mQuadVBO);
+    mQuadVBO = 0;
+  }
+
+  if (mTriangleVBO) {
+    ctx->fDeleteBuffers(1, &mTriangleVBO);
+    mTriangleVBO = 0;
+  }
+
+  mGLContext->MakeCurrent();
+
+  if (mPreviousFrameDoneSync) {
+    mGLContext->fDeleteSync(mPreviousFrameDoneSync);
+    mPreviousFrameDoneSync = nullptr;
+  }
+
+  if (mThisFrameDoneSync) {
+    mGLContext->fDeleteSync(mThisFrameDoneSync);
+    mThisFrameDoneSync = nullptr;
+  }
+
+  if (mOwnsGLContext) {
+    // On the main thread the Widget will be destroyed soon and calling
+    // MakeCurrent after that could cause a crash (at least with GLX, see bug
+    // 1059793), unless context is marked as destroyed. There may be some
+    // textures still alive that will try to call MakeCurrent on the context so
+    // let's make sure it is marked destroyed now.
+    mGLContext->MarkDestroyed();
+  }
+
+  mGLContext = nullptr;
+}
+
+bool CompositorOGL::Initialize(GLContext* aGLContext,
+                               RefPtr<ShaderProgramOGLsHolder> aProgramsHolder,
+                               nsCString* const out_failureReason) {
+  MOZ_ASSERT(!mDestroyed);
+  MOZ_ASSERT(!mGLContext);
+
+  mGLContext = aGLContext;
+  mProgramsHolder = aProgramsHolder;
+  mOwnsGLContext = false;
+
+  return Initialize(out_failureReason);
+}
+
+bool CompositorOGL::Initialize(nsCString* const out_failureReason) {
+  ScopedGfxFeatureReporter reporter("GL Layers");
+
+  // Do not allow double initialization
+  MOZ_ASSERT(mGLContext == nullptr || !mOwnsGLContext,
+             "Don't reinitialize CompositorOGL");
+
+  if (!mGLContext) {
+    MOZ_ASSERT(mOwnsGLContext);
+    mGLContext = CreateContext();
+  }
+
+#ifdef MOZ_WIDGET_ANDROID
+  if (!mGLContext) {
+    *out_failureReason = "FEATURE_FAILURE_OPENGL_NO_ANDROID_CONTEXT";
+    MOZ_CRASH("We need a context on Android");
+  }
+#endif
+
+  if (!mGLContext) {
+    *out_failureReason = "FEATURE_FAILURE_OPENGL_CREATE_CONTEXT";
+    return false;
+  }
+
+  if (!mProgramsHolder) {
+    mProgramsHolder = new ShaderProgramOGLsHolder(mGLContext);
+  }
+
+  MakeCurrent();
+
+  mHasBGRA = mGLContext->IsExtensionSupported(
+                 gl::GLContext::EXT_texture_format_BGRA8888) ||
+             mGLContext->IsExtensionSupported(gl::GLContext::EXT_bgra);
+
+  mGLContext->fBlendFuncSeparate(LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA,
+                                 LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA);
+  mGLContext->fEnable(LOCAL_GL_BLEND);
+
+  // initialise a common shader to check that we can actually compile a shader
+  RefPtr<EffectNV12> effect =
+      new EffectNV12(nullptr, YUVColorSpace::BT601, ColorRange::LIMITED,
+                     ColorDepth::COLOR_8, SamplingFilter::GOOD);
+  ShaderConfigOGL config = GetShaderConfigFor(effect);
+  if (!GetShaderProgramFor(config)) {
+    *out_failureReason = "FEATURE_FAILURE_OPENGL_COMPILE_SHADER";
+    return false;
+  }
+
+  if (mGLContext->WorkAroundDriverBugs()) {
+    /**
+     * We'll test the ability here to bind NPOT textures to a framebuffer, if
+     * this fails we'll try ARB_texture_rectangle.
+     */
+
+    GLenum textureTargets[] = {LOCAL_GL_TEXTURE_2D, LOCAL_GL_NONE};
+
+    if (!mGLContext->IsGLES()) {
+      // No TEXTURE_RECTANGLE_ARB available on ES2
+      textureTargets[1] = LOCAL_GL_TEXTURE_RECTANGLE_ARB;
+    }
+
+    mFBOTextureTarget = LOCAL_GL_NONE;
+
+    GLuint testFBO = 0;
+    mGLContext->fGenFramebuffers(1, &testFBO);
+    GLuint testTexture = 0;
+
+    for (uint32_t i = 0; i < ArrayLength(textureTargets); i++) {
+      GLenum target = textureTargets[i];
+      if (!target) continue;
+
+      mGLContext->fGenTextures(1, &testTexture);
+      mGLContext->fBindTexture(target, testTexture);
+      mGLContext->fTexParameteri(target, LOCAL_GL_TEXTURE_MIN_FILTER,
+                                 LOCAL_GL_NEAREST);
+      mGLContext->fTexParameteri(target, LOCAL_GL_TEXTURE_MAG_FILTER,
+                                 LOCAL_GL_NEAREST);
+      mGLContext->fTexImage2D(
+          target, 0, LOCAL_GL_RGBA, 5, 3, /* sufficiently NPOT */
+          0, LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, nullptr);
+
+      // unbind this texture, in preparation for binding it to the FBO
+      mGLContext->fBindTexture(target, 0);
+
+      mGLContext->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, testFBO);
+      mGLContext->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER,
+                                        LOCAL_GL_COLOR_ATTACHMENT0, target,
+                                        testTexture, 0);
+
+      if (mGLContext->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER) ==
+          LOCAL_GL_FRAMEBUFFER_COMPLETE) {
+        mFBOTextureTarget = target;
+        mGLContext->fDeleteTextures(1, &testTexture);
+        break;
+      }
+
+      mGLContext->fDeleteTextures(1, &testTexture);
+    }
+
+    if (testFBO) {
+      mGLContext->fDeleteFramebuffers(1, &testFBO);
+    }
+
+    if (mFBOTextureTarget == LOCAL_GL_NONE) {
+      /* Unable to find a texture target that works with FBOs and NPOT textures
+       */
+      *out_failureReason = "FEATURE_FAILURE_OPENGL_NO_TEXTURE_TARGET";
+      return false;
+    }
+  } else {
+    // not trying to work around driver bugs, so TEXTURE_2D should just work
+    mFBOTextureTarget = LOCAL_GL_TEXTURE_2D;
+  }
+
+  // back to default framebuffer, to avoid confusion
+  mGLContext->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, 0);
+
+  if (mFBOTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE_ARB) {
+    /* If we're using TEXTURE_RECTANGLE, then we must have the ARB
+     * extension -- the EXT variant does not provide support for
+     * texture rectangle access inside GLSL (sampler2DRect,
+     * texture2DRect).
+     */
+    if (!mGLContext->IsExtensionSupported(
+            gl::GLContext::ARB_texture_rectangle)) {
+      *out_failureReason = "FEATURE_FAILURE_OPENGL_ARB_EXT";
+      return false;
+    }
+  }
+
+  // Create a VBO for triangle vertices.
+  mGLContext->fGenBuffers(1, &mTriangleVBO);
+
+  /* Create a simple quad VBO */
+  mGLContext->fGenBuffers(1, &mQuadVBO);
+
+  // 4 quads, with the number of the quad (vertexID) encoded in w.
+  GLfloat vertices[] = {
+      0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
+      1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f,
+
+      0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f,
+      1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f,
+
+      0.0f, 0.0f, 0.0f, 2.0f, 1.0f, 0.0f, 0.0f, 2.0f, 0.0f, 1.0f, 0.0f, 2.0f,
+      1.0f, 0.0f, 0.0f, 2.0f, 0.0f, 1.0f, 0.0f, 2.0f, 1.0f, 1.0f, 0.0f, 2.0f,
+
+      0.0f, 0.0f, 0.0f, 3.0f, 1.0f, 0.0f, 0.0f, 3.0f, 0.0f, 1.0f, 0.0f, 3.0f,
+      1.0f, 0.0f, 0.0f, 3.0f, 0.0f, 1.0f, 0.0f, 3.0f, 1.0f, 1.0f, 0.0f, 3.0f,
+  };
+  HeapCopyOfStackArray<GLfloat> verticesOnHeap(vertices);
+
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mQuadVBO);
+  mGLContext->fBufferData(LOCAL_GL_ARRAY_BUFFER, verticesOnHeap.ByteLength(),
+                          verticesOnHeap.Data(), LOCAL_GL_STATIC_DRAW);
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+
+  nsCOMPtr<nsIConsoleService> console(
+      do_GetService(NS_CONSOLESERVICE_CONTRACTID));
+
+  if (console) {
+    nsString msg;
+    msg += nsLiteralString(
+        u"OpenGL compositor Initialized Succesfully.\nVersion: ");
+    msg += NS_ConvertUTF8toUTF16(nsDependentCString(
+        (const char*)mGLContext->fGetString(LOCAL_GL_VERSION)));
+    msg += u"\nVendor: "_ns;
+    msg += NS_ConvertUTF8toUTF16(nsDependentCString(
+        (const char*)mGLContext->fGetString(LOCAL_GL_VENDOR)));
+    msg += u"\nRenderer: "_ns;
+    msg += NS_ConvertUTF8toUTF16(nsDependentCString(
+        (const char*)mGLContext->fGetString(LOCAL_GL_RENDERER)));
+    msg += u"\nFBO Texture Target: "_ns;
+    if (mFBOTextureTarget == LOCAL_GL_TEXTURE_2D)
+      msg += u"TEXTURE_2D"_ns;
+    else
+      msg += u"TEXTURE_RECTANGLE"_ns;
+    console->LogStringMessage(msg.get());
+  }
+
+  reporter.SetSuccessful();
+
+  return true;
+}
+
+/*
+ * Returns a size that is equal to, or larger than and closest to,
+ * aSize where both width and height are powers of two.
+ * If the OpenGL setup is capable of using non-POT textures,
+ * then it will just return aSize.
+ */
+static IntSize CalculatePOTSize(const IntSize& aSize, GLContext* gl) {
+  if (CanUploadNonPowerOfTwo(gl)) return aSize;
+
+  return IntSize(RoundUpPow2(aSize.width), RoundUpPow2(aSize.height));
+}
+
+gfx::Rect CompositorOGL::GetTextureCoordinates(gfx::Rect textureRect,
+                                               TextureSource* aTexture) {
+  // If the OpenGL setup does not support non-power-of-two textures then the
+  // texture's width and height will have been increased to the next
+  // power-of-two (unless already a power of two). In that case we must scale
+  // the texture coordinates to account for that.
+  if (!CanUploadNonPowerOfTwo(mGLContext)) {
+    const IntSize& textureSize = aTexture->GetSize();
+    const IntSize potSize = CalculatePOTSize(textureSize, mGLContext);
+    if (potSize != textureSize) {
+      const float xScale = (float)textureSize.width / (float)potSize.width;
+      const float yScale = (float)textureSize.height / (float)potSize.height;
+      textureRect.Scale(xScale, yScale);
+    }
+  }
+
+  return textureRect;
+}
+
+void CompositorOGL::PrepareViewport(CompositingRenderTargetOGL* aRenderTarget) {
+  MOZ_ASSERT(aRenderTarget);
+  // Logical surface size.
+  const gfx::IntSize& size = aRenderTarget->GetSize();
+  // Physical surface size.
+  const gfx::IntSize& phySize = aRenderTarget->GetPhysicalSize();
+
+  // Set the viewport correctly.
+  mGLContext->fViewport(mSurfaceOrigin.x, mSurfaceOrigin.y, phySize.width,
+                        phySize.height);
+
+  mViewportSize = size;
+
+  if (!aRenderTarget->HasComplexProjection()) {
+    // We flip the view matrix around so that everything is right-side up; we're
+    // drawing directly into the window's back buffer, so this keeps things
+    // looking correct.
+    // XXX: We keep track of whether the window size changed, so we could skip
+    // this update if it hadn't changed since the last call.
+
+    // Matrix to transform (0, 0, aWidth, aHeight) to viewport space (-1.0, 1.0,
+    // 2, 2) and flip the contents.
+    Matrix viewMatrix;
+    viewMatrix.PreTranslate(-1.0, 1.0);
+    viewMatrix.PreScale(2.0f / float(size.width), 2.0f / float(size.height));
+    viewMatrix.PreScale(1.0f, -1.0f);
+
+    MOZ_ASSERT(mCurrentRenderTarget, "No destination");
+
+    Matrix4x4 matrix3d = Matrix4x4::From2D(viewMatrix);
+    matrix3d._33 = 0.0f;
+    mProjMatrix = matrix3d;
+    mGLContext->fDepthRange(0.0f, 1.0f);
+  } else {
+    bool depthEnable;
+    float zNear, zFar;
+    aRenderTarget->GetProjection(mProjMatrix, depthEnable, zNear, zFar);
+    mGLContext->fDepthRange(zNear, zFar);
+  }
+}
+
+already_AddRefed<CompositingRenderTarget> CompositorOGL::CreateRenderTarget(
+    const IntRect& aRect, SurfaceInitMode aInit) {
+  MOZ_ASSERT(!aRect.IsZeroArea(),
+             "Trying to create a render target of invalid size");
+
+  if (aRect.IsZeroArea()) {
+    return nullptr;
+  }
+
+  if (!gl()) {
+    // CompositingRenderTargetOGL does not work without a gl context.
+    return nullptr;
+  }
+
+  GLuint tex = 0;
+  GLuint fbo = 0;
+  IntRect rect = aRect;
+  IntSize fboSize;
+  CreateFBOWithTexture(rect, false, 0, &fbo, &tex, &fboSize);
+  return CompositingRenderTargetOGL::CreateForNewFBOAndTakeOwnership(
+      this, tex, fbo, aRect, aRect.TopLeft(), aRect.Size(), mFBOTextureTarget,
+      aInit);
+}
+
+void CompositorOGL::SetRenderTarget(CompositingRenderTarget* aSurface) {
+  MOZ_ASSERT(aSurface);
+  CompositingRenderTargetOGL* surface =
+      static_cast<CompositingRenderTargetOGL*>(aSurface);
+  if (mCurrentRenderTarget != surface) {
+    mCurrentRenderTarget = surface;
+    surface->BindRenderTarget();
+  }
+
+  PrepareViewport(mCurrentRenderTarget);
+}
+
+already_AddRefed<CompositingRenderTarget>
+CompositorOGL::GetCurrentRenderTarget() const {
+  return do_AddRef(mCurrentRenderTarget);
+}
+
+already_AddRefed<CompositingRenderTarget> CompositorOGL::GetWindowRenderTarget()
+    const {
+  return do_AddRef(mWindowRenderTarget);
+}
+
+already_AddRefed<AsyncReadbackBuffer> CompositorOGL::CreateAsyncReadbackBuffer(
+    const IntSize& aSize) {
+  return MakeAndAddRef<AsyncReadbackBufferOGL>(mGLContext, aSize);
+}
+
+bool CompositorOGL::ReadbackRenderTarget(CompositingRenderTarget* aSource,
+                                         AsyncReadbackBuffer* aDest) {
+  IntSize size = aSource->GetSize();
+  MOZ_RELEASE_ASSERT(aDest->GetSize() == size);
+
+  RefPtr<CompositingRenderTarget> previousTarget = GetCurrentRenderTarget();
+  if (previousTarget != aSource) {
+    SetRenderTarget(aSource);
+  }
+
+  ScopedPackState scopedPackState(mGLContext);
+  static_cast<AsyncReadbackBufferOGL*>(aDest)->Bind();
+
+  mGLContext->fReadPixels(0, 0, size.width, size.height, LOCAL_GL_RGBA,
+                          LOCAL_GL_UNSIGNED_BYTE, 0);
+
+  if (previousTarget != aSource) {
+    SetRenderTarget(previousTarget);
+  }
+  return true;
+}
+
+bool CompositorOGL::BlitRenderTarget(CompositingRenderTarget* aSource,
+                                     const gfx::IntSize& aSourceSize,
+                                     const gfx::IntSize& aDestSize) {
+  if (!mGLContext->IsSupported(GLFeature::framebuffer_blit)) {
+    return false;
+  }
+  CompositingRenderTargetOGL* source =
+      static_cast<CompositingRenderTargetOGL*>(aSource);
+  GLuint srcFBO = source->GetFBO();
+  GLuint destFBO = mCurrentRenderTarget->GetFBO();
+  mGLContext->BlitHelper()->BlitFramebufferToFramebuffer(
+      srcFBO, destFBO, IntRect(IntPoint(), aSourceSize),
+      IntRect(IntPoint(), aDestSize), LOCAL_GL_LINEAR);
+  return true;
+}
+
+static GLenum GetFrameBufferInternalFormat(
+    GLContext* gl, GLuint aFrameBuffer,
+    mozilla::widget::CompositorWidget* aWidget) {
+  if (aFrameBuffer == 0) {  // default framebuffer
+    return aWidget->GetGLFrameBufferFormat();
+  }
+  return LOCAL_GL_RGBA;
+}
+
+Maybe<IntRect> CompositorOGL::BeginFrameForWindow(
+    const nsIntRegion& aInvalidRegion, const Maybe<IntRect>& aClipRect,
+    const IntRect& aRenderBounds, const nsIntRegion& aOpaqueRegion) {
+  MOZ_RELEASE_ASSERT(!mTarget, "mTarget not cleared properly");
+  return BeginFrame(aInvalidRegion, aClipRect, aRenderBounds, aOpaqueRegion);
+}
+
+Maybe<IntRect> CompositorOGL::BeginFrame(const nsIntRegion& aInvalidRegion,
+                                         const Maybe<IntRect>& aClipRect,
+                                         const IntRect& aRenderBounds,
+                                         const nsIntRegion& aOpaqueRegion) {
+  AUTO_PROFILER_LABEL("CompositorOGL::BeginFrame", GRAPHICS);
+
+  MOZ_ASSERT(!mFrameInProgress,
+             "frame still in progress (should have called EndFrame");
+
+  IntRect rect;
+  if (mUseExternalSurfaceSize) {
+    rect = IntRect(IntPoint(), mSurfaceSize);
+  } else {
+    rect = aRenderBounds;
+  }
+
+  // We can't draw anything to something with no area
+  // so just return
+  if (rect.IsZeroArea()) {
+    return Nothing();
+  }
+
+  // If the widget size changed, we have to force a MakeCurrent
+  // to make sure that GL sees the updated widget size.
+  if (mWidgetSize.ToUnknownSize() != rect.Size()) {
+    MakeCurrent(ForceMakeCurrent);
+
+    mWidgetSize = LayoutDeviceIntSize::FromUnknownSize(rect.Size());
+#ifdef MOZ_WAYLAND
+    if (mWidget && mWidget->AsGTK()) {
+      mWidget->AsGTK()->SetEGLNativeWindowSize(mWidgetSize);
+    }
+#endif
+  } else {
+    MakeCurrent();
+  }
+
+#ifdef MOZ_WIDGET_ANDROID
+  java::GeckoSurfaceTexture::DestroyUnused((int64_t)mGLContext.get());
+  mGLContext->MakeCurrent();  // DestroyUnused can change the current context!
+#endif
+
+  // Default blend function implements "OVER"
+  mGLContext->fBlendFuncSeparate(LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA,
+                                 LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA);
+  mGLContext->fEnable(LOCAL_GL_BLEND);
+
+  RefPtr<CompositingRenderTarget> rt;
+  if (mCanRenderToDefaultFramebuffer) {
+    rt = CompositingRenderTargetOGL::CreateForWindow(this, rect.Size());
+  } else if (mTarget) {
+    rt = CreateRenderTarget(rect, INIT_MODE_CLEAR);
+  } else {
+    MOZ_CRASH("Unexpected call");
+  }
+
+  if (!rt) {
+    return Nothing();
+  }
+
+  // We're about to actually draw a frame.
+  mFrameInProgress = true;
+
+  SetRenderTarget(rt);
+  mWindowRenderTarget = mCurrentRenderTarget;
+
+  for (auto iter = aInvalidRegion.RectIter(); !iter.Done(); iter.Next()) {
+    const IntRect& r = iter.Get();
+    mCurrentFrameInvalidRegion.OrWith(
+        IntRect(r.X(), FlipY(r.YMost()), r.Width(), r.Height()));
+  }
+  // Check to see if there is any transparent dirty region that would require
+  // clearing. If not, just invalidate the framebuffer if supported.
+  // TODO: Currently we initialize the clear region to the widget bounds as
+  // SwapBuffers will update the entire framebuffer. On platforms that support
+  // damage regions, we could initialize this to mCurrentFrameInvalidRegion.
+  IntRegion regionToClear(rect);
+  regionToClear.SubOut(aOpaqueRegion);
+  GLbitfield clearBits = LOCAL_GL_DEPTH_BUFFER_BIT;
+  if (regionToClear.IsEmpty() &&
+      mGLContext->IsSupported(GLFeature::invalidate_framebuffer)) {
+    GLenum attachments[] = {LOCAL_GL_COLOR};
+    mGLContext->fInvalidateFramebuffer(
+        LOCAL_GL_FRAMEBUFFER, MOZ_ARRAY_LENGTH(attachments), attachments);
+  } else {
+    clearBits |= LOCAL_GL_COLOR_BUFFER_BIT;
+  }
+
+#if defined(MOZ_WIDGET_ANDROID)
+  if ((mSurfaceOrigin.x > 0) || (mSurfaceOrigin.y > 0)) {
+    mGLContext->fClearColor(
+        StaticPrefs::gfx_compositor_override_clear_color_r(),
+        StaticPrefs::gfx_compositor_override_clear_color_g(),
+        StaticPrefs::gfx_compositor_override_clear_color_b(),
+        StaticPrefs::gfx_compositor_override_clear_color_a());
+  } else {
+    mGLContext->fClearColor(mClearColor.r, mClearColor.g, mClearColor.b,
+                            mClearColor.a);
+  }
+#else
+  mGLContext->fClearColor(mClearColor.r, mClearColor.g, mClearColor.b,
+                          mClearColor.a);
+#endif  // defined(MOZ_WIDGET_ANDROID)
+  mGLContext->fClear(clearBits);
+
+  return Some(rect);
+}
+
+void CompositorOGL::CreateFBOWithTexture(const gfx::IntRect& aRect,
+                                         bool aCopyFromSource,
+                                         GLuint aSourceFrameBuffer,
+                                         GLuint* aFBO, GLuint* aTexture,
+                                         gfx::IntSize* aAllocSize) {
+  *aTexture =
+      CreateTexture(aRect, aCopyFromSource, aSourceFrameBuffer, aAllocSize);
+  mGLContext->fGenFramebuffers(1, aFBO);
+}
+
+// Should be called after calls to fReadPixels or fCopyTexImage2D, and other
+// GL read calls.
+static void WorkAroundAppleIntelHD3000GraphicsGLDriverBug(GLContext* aGL) {
+#ifdef XP_MACOSX
+  if (aGL->WorkAroundDriverBugs() &&
+      aGL->Renderer() == GLRenderer::IntelHD3000) {
+    // Work around a bug in the Apple Intel HD Graphics 3000 driver (bug
+    // 1586627, filed with Apple as FB7379358). This bug has been found present
+    // on 10.9.3 and on 10.13.6, so it likely affects all shipped versions of
+    // this driver. (macOS 10.14 does not support this GPU.)
+    // The bug manifests as follows: Reading from a framebuffer puts that
+    // framebuffer into a state such that deleting that framebuffer can break
+    // other framebuffers in certain cases. More specifically, if you have two
+    // framebuffers A and B, the following sequence of events breaks subsequent
+    // drawing to B:
+    //  1. A becomes "most recently read-from framebuffer".
+    //  2. B is drawn to.
+    //  3. A is deleted, and other GL state (such as GL_SCISSOR enabled state)
+    //     is touched.
+    //  4. B is drawn to again.
+    // Now all draws to framebuffer B, including the draw from step 4, will
+    // render at the wrong position and upside down.
+    //
+    // When AfterGLReadCall() is called, the currently bound framebuffer is the
+    // framebuffer that has been read from most recently. So in the presence of
+    // this bug, deleting this framebuffer has now become dangerous. We work
+    // around the bug by creating a new short-lived framebuffer, making that new
+    // framebuffer the most recently read-from framebuffer (using
+    // glCopyTexImage2D), and then deleting it under controlled circumstances.
+    // This deletion is not affected by the bug because our deletion call is not
+    // interleaved with draw calls to another framebuffer and a touching of the
+    // GL scissor enabled state.
+
+    ScopedTexture texForReading(aGL);
+    {
+      // Initialize a 1x1 texture.
+      ScopedBindTexture autoBindTexForReading(aGL, texForReading);
+      aGL->fTexImage2D(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_RGBA, 1, 1, 0,
+                       LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, nullptr);
+      aGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MIN_FILTER,
+                          LOCAL_GL_LINEAR);
+      aGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MAG_FILTER,
+                          LOCAL_GL_LINEAR);
+    }
+    // Make a framebuffer around the texture.
+    ScopedFramebufferForTexture autoFBForReading(aGL, texForReading);
+    if (autoFBForReading.IsComplete()) {
+      // "Read" from the framebuffer, by initializing a new texture using
+      // glCopyTexImage2D. This flips the bad bit on autoFBForReading.FB().
+      ScopedBindFramebuffer autoFB(aGL, autoFBForReading.FB());
+      ScopedTexture texReadingDest(aGL);
+      ScopedBindTexture autoBindTexReadingDest(aGL, texReadingDest);
+      aGL->fCopyTexImage2D(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_RGBA, 0, 0, 1, 1,
+                           0);
+    }
+    // When autoFBForReading goes out of scope, the "poisoned" framebuffer is
+    // deleted, and the bad state seems to go away along with it.
+  }
+#endif
+}
+
+GLuint CompositorOGL::CreateTexture(const IntRect& aRect, bool aCopyFromSource,
+                                    GLuint aSourceFrameBuffer,
+                                    IntSize* aAllocSize) {
+  // we're about to create a framebuffer backed by textures to use as an
+  // intermediate surface. What to do if its size (as given by aRect) would
+  // exceed the maximum texture size supported by the GL? The present code
+  // chooses the compromise of just clamping the framebuffer's size to the max
+  // supported size. This gives us a lower resolution rendering of the
+  // intermediate surface (children layers). See bug 827170 for a discussion.
+  IntRect clampedRect = aRect;
+  int32_t maxTexSize = GetMaxTextureSize();
+  clampedRect.SetWidth(std::min(clampedRect.Width(), maxTexSize));
+  clampedRect.SetHeight(std::min(clampedRect.Height(), maxTexSize));
+
+  auto clampedRectWidth = clampedRect.Width();
+  auto clampedRectHeight = clampedRect.Height();
+
+  GLuint tex;
+
+  mGLContext->fActiveTexture(LOCAL_GL_TEXTURE0);
+  mGLContext->fGenTextures(1, &tex);
+  mGLContext->fBindTexture(mFBOTextureTarget, tex);
+
+  if (aCopyFromSource) {
+    GLuint curFBO = mCurrentRenderTarget->GetFBO();
+    if (curFBO != aSourceFrameBuffer) {
+      mGLContext->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, aSourceFrameBuffer);
+    }
+
+    // We're going to create an RGBA temporary fbo.  But to
+    // CopyTexImage() from the current framebuffer, the framebuffer's
+    // format has to be compatible with the new texture's.  So we
+    // check the format of the framebuffer here and take a slow path
+    // if it's incompatible.
+    GLenum format =
+        GetFrameBufferInternalFormat(gl(), aSourceFrameBuffer, mWidget);
+
+    bool isFormatCompatibleWithRGBA =
+        gl()->IsGLES() ? (format == LOCAL_GL_RGBA) : true;
+
+    if (isFormatCompatibleWithRGBA) {
+      mGLContext->fCopyTexImage2D(mFBOTextureTarget, 0, LOCAL_GL_RGBA,
+                                  clampedRect.X(), FlipY(clampedRect.YMost()),
+                                  clampedRectWidth, clampedRectHeight, 0);
+      WorkAroundAppleIntelHD3000GraphicsGLDriverBug(mGLContext);
+    } else {
+      // Curses, incompatible formats.  Take a slow path.
+
+      // RGBA
+      size_t bufferSize = clampedRectWidth * clampedRectHeight * 4;
+      auto buf = MakeUnique<uint8_t[]>(bufferSize);
+
+      mGLContext->fReadPixels(clampedRect.X(), clampedRect.Y(),
+                              clampedRectWidth, clampedRectHeight,
+                              LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, buf.get());
+      WorkAroundAppleIntelHD3000GraphicsGLDriverBug(mGLContext);
+      mGLContext->fTexImage2D(mFBOTextureTarget, 0, LOCAL_GL_RGBA,
+                              clampedRectWidth, clampedRectHeight, 0,
+                              LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, buf.get());
+    }
+
+    GLenum error = mGLContext->fGetError();
+    if (error != LOCAL_GL_NO_ERROR) {
+      nsAutoCString msg;
+      msg.AppendPrintf(
+          "Texture initialization failed! -- error 0x%x, Source %d, Source "
+          "format %d,  RGBA Compat %d",
+          error, aSourceFrameBuffer, format, isFormatCompatibleWithRGBA);
+      NS_ERROR(msg.get());
+    }
+  } else {
+    mGLContext->fTexImage2D(mFBOTextureTarget, 0, LOCAL_GL_RGBA,
+                            clampedRectWidth, clampedRectHeight, 0,
+                            LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, nullptr);
+  }
+  mGLContext->fTexParameteri(mFBOTextureTarget, LOCAL_GL_TEXTURE_MIN_FILTER,
+                             LOCAL_GL_LINEAR);
+  mGLContext->fTexParameteri(mFBOTextureTarget, LOCAL_GL_TEXTURE_MAG_FILTER,
+                             LOCAL_GL_LINEAR);
+  mGLContext->fTexParameteri(mFBOTextureTarget, LOCAL_GL_TEXTURE_WRAP_S,
+                             LOCAL_GL_CLAMP_TO_EDGE);
+  mGLContext->fTexParameteri(mFBOTextureTarget, LOCAL_GL_TEXTURE_WRAP_T,
+                             LOCAL_GL_CLAMP_TO_EDGE);
+  mGLContext->fBindTexture(mFBOTextureTarget, 0);
+
+  if (aAllocSize) {
+    aAllocSize->width = clampedRectWidth;
+    aAllocSize->height = clampedRectHeight;
+  }
+
+  return tex;
+}
+
+ShaderConfigOGL CompositorOGL::GetShaderConfigFor(Effect* aEffect,
+                                                  bool aDEAAEnabled) const {
+  ShaderConfigOGL config;
+
+  switch (aEffect->mType) {
+    case EffectTypes::YCBCR: {
+      config.SetYCbCr(true);
+      EffectYCbCr* effectYCbCr = static_cast<EffectYCbCr*>(aEffect);
+      config.SetColorMultiplier(
+          RescalingFactorForColorDepth(effectYCbCr->mColorDepth));
+      config.SetTextureTarget(
+          effectYCbCr->mTexture->AsSourceOGL()->GetTextureTarget());
+      break;
+    }
+    case EffectTypes::NV12:
+      config.SetNV12(true);
+      if (gl()->IsExtensionSupported(gl::GLContext::ARB_texture_rectangle)) {
+        config.SetTextureTarget(LOCAL_GL_TEXTURE_RECTANGLE_ARB);
+      } else {
+        config.SetTextureTarget(LOCAL_GL_TEXTURE_2D);
+      }
+      break;
+    default: {
+      MOZ_ASSERT(aEffect->mType == EffectTypes::RGB);
+      TexturedEffect* texturedEffect = static_cast<TexturedEffect*>(aEffect);
+      TextureSourceOGL* source = texturedEffect->mTexture->AsSourceOGL();
+      MOZ_ASSERT_IF(
+          source->GetTextureTarget() == LOCAL_GL_TEXTURE_EXTERNAL,
+          source->GetFormat() == gfx::SurfaceFormat::R8G8B8A8 ||
+              source->GetFormat() == gfx::SurfaceFormat::R8G8B8X8 ||
+              source->GetFormat() == gfx::SurfaceFormat::B8G8R8A8 ||
+              source->GetFormat() == gfx::SurfaceFormat::B8G8R8X8 ||
+              source->GetFormat() == gfx::SurfaceFormat::R5G6B5_UINT16);
+      MOZ_ASSERT_IF(
+          source->GetTextureTarget() == LOCAL_GL_TEXTURE_RECTANGLE_ARB,
+          source->GetFormat() == gfx::SurfaceFormat::R8G8B8A8 ||
+              source->GetFormat() == gfx::SurfaceFormat::R8G8B8X8 ||
+              source->GetFormat() == gfx::SurfaceFormat::R5G6B5_UINT16 ||
+              source->GetFormat() == gfx::SurfaceFormat::YUV422);
+      config = ShaderConfigFromTargetAndFormat(source->GetTextureTarget(),
+                                               source->GetFormat());
+      if (!texturedEffect->mPremultiplied) {
+        config.SetNoPremultipliedAlpha();
+      }
+      break;
+    }
+  }
+  config.SetDEAA(aDEAAEnabled);
+  return config;
+}
+
+ShaderProgramOGL* CompositorOGL::GetShaderProgramFor(
+    const ShaderConfigOGL& aConfig) {
+  ShaderProgramOGL* shader = mProgramsHolder->GetShaderProgramFor(aConfig);
+  return shader;
+}
+
+void CompositorOGL::ResetProgram() { mProgramsHolder->ResetCurrentProgram(); }
+
+static bool SetBlendMode(GLContext* aGL, gfx::CompositionOp aBlendMode,
+                         bool aIsPremultiplied = true) {
+  if (BlendOpIsMixBlendMode(aBlendMode)) {
+    // Mix-blend modes require an extra step (or more) that cannot be expressed
+    // in the fixed-function blending capabilities of opengl. We handle them
+    // separately in shaders, and the shaders assume we will use our default
+    // blend function for compositing (premultiplied OP_OVER).
+    return false;
+  }
+  if (aBlendMode == gfx::CompositionOp::OP_OVER && aIsPremultiplied) {
+    return false;
+  }
+
+  GLenum srcBlend;
+  GLenum dstBlend;
+  GLenum srcAlphaBlend = LOCAL_GL_ONE;
+  GLenum dstAlphaBlend = LOCAL_GL_ONE_MINUS_SRC_ALPHA;
+
+  switch (aBlendMode) {
+    case gfx::CompositionOp::OP_OVER:
+      MOZ_ASSERT(!aIsPremultiplied);
+      srcBlend = LOCAL_GL_SRC_ALPHA;
+      dstBlend = LOCAL_GL_ONE_MINUS_SRC_ALPHA;
+      break;
+    case gfx::CompositionOp::OP_SOURCE:
+      srcBlend = aIsPremultiplied ? LOCAL_GL_ONE : LOCAL_GL_SRC_ALPHA;
+      dstBlend = LOCAL_GL_ZERO;
+      srcAlphaBlend = LOCAL_GL_ONE;
+      dstAlphaBlend = LOCAL_GL_ZERO;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unsupported blend mode!");
+      return false;
+  }
+
+  aGL->fBlendFuncSeparate(srcBlend, dstBlend, srcAlphaBlend, dstAlphaBlend);
+  return true;
+}
+
+gfx::Point3D CompositorOGL::GetLineCoefficients(const gfx::Point& aPoint1,
+                                                const gfx::Point& aPoint2) {
+  // Return standard coefficients for a line between aPoint1 and aPoint2
+  // for standard line equation:
+  //
+  // Ax + By + C = 0
+  //
+  // A = (p1.y – p2.y)
+  // B = (p2.x – p1.x)
+  // C = (p1.x * p2.y) – (p2.x * p1.y)
+
+  gfx::Point3D coeffecients;
+  coeffecients.x = aPoint1.y - aPoint2.y;
+  coeffecients.y = aPoint2.x - aPoint1.x;
+  coeffecients.z =
+      aPoint1.x.value * aPoint2.y.value - aPoint2.x.value * aPoint1.y.value;
+
+  coeffecients *= 1.0f / sqrtf(coeffecients.x * coeffecients.x +
+                               coeffecients.y * coeffecients.y);
+
+  // Offset outwards by 0.5 pixel as the edge is considered to be 1 pixel
+  // wide and included within the interior of the polygon
+  coeffecients.z += 0.5f;
+
+  return coeffecients;
+}
+
+void CompositorOGL::DrawQuad(const Rect& aRect, const IntRect& aClipRect,
+                             const EffectChain& aEffectChain, Float aOpacity,
+                             const gfx::Matrix4x4& aTransform,
+                             const gfx::Rect& aVisibleRect) {
+  AUTO_PROFILER_LABEL("CompositorOGL::DrawQuad", GRAPHICS);
+
+  DrawGeometry(aRect, aRect, aClipRect, aEffectChain, aOpacity, aTransform,
+               aVisibleRect);
+}
+
+template <typename Geometry>
+void CompositorOGL::DrawGeometry(const Geometry& aGeometry,
+                                 const gfx::Rect& aRect,
+                                 const gfx::IntRect& aClipRect,
+                                 const EffectChain& aEffectChain,
+                                 gfx::Float aOpacity,
+                                 const gfx::Matrix4x4& aTransform,
+                                 const gfx::Rect& aVisibleRect) {
+  MOZ_ASSERT(mFrameInProgress, "frame not started");
+  MOZ_ASSERT(mCurrentRenderTarget, "No destination");
+
+  MakeCurrent();
+
+  // Convert aClipRect into render target space, and intersect it with the
+  // render target's clip.
+  IntRect clipRect = aClipRect + mCurrentRenderTarget->GetClipSpaceOrigin();
+  if (Maybe<IntRect> rtClip = mCurrentRenderTarget->GetClipRect()) {
+    clipRect = clipRect.Intersect(*rtClip);
+  }
+
+  Rect destRect = aTransform.TransformAndClipBounds(
+      aRect, Rect(mCurrentRenderTarget->GetRect().Intersect(clipRect)));
+  if (destRect.IsEmpty()) {
+    return;
+  }
+
+  // Move clipRect into device space.
+  IntPoint offset = mCurrentRenderTarget->GetOrigin();
+  clipRect -= offset;
+
+  if (!mTarget && mCurrentRenderTarget->IsWindow()) {
+    clipRect.MoveBy(mSurfaceOrigin.x, -mSurfaceOrigin.y);
+  }
+
+  ScopedGLState scopedScissorTestState(mGLContext, LOCAL_GL_SCISSOR_TEST, true);
+  ScopedScissorRect autoScissorRect(mGLContext, clipRect.X(),
+                                    FlipY(clipRect.Y() + clipRect.Height()),
+                                    clipRect.Width(), clipRect.Height());
+
+  // Only apply DEAA to quads that have been transformed such that aliasing
+  // could be visible
+  bool bEnableAA = StaticPrefs::layers_deaa_enabled() &&
+                   !aTransform.Is2DIntegerTranslation();
+
+  ShaderConfigOGL config =
+      GetShaderConfigFor(aEffectChain.mPrimaryEffect, bEnableAA);
+
+  config.SetOpacity(aOpacity != 1.f);
+  ApplyPrimitiveConfig(config, aGeometry);
+
+  ShaderProgramOGL* program = mProgramsHolder->ActivateProgram(config);
+  if (!program) {
+    return;
+  }
+  program->SetProjectionMatrix(mProjMatrix);
+  program->SetLayerTransform(aTransform);
+  program->SetRenderOffset(offset.x, offset.y);
+
+  if (aOpacity != 1.f) program->SetLayerOpacity(aOpacity);
+
+  if (config.mFeatures & ENABLE_TEXTURE_RECT) {
+    TextureSourceOGL* source = nullptr;
+    TexturedEffect* texturedEffect =
+        static_cast<TexturedEffect*>(aEffectChain.mPrimaryEffect.get());
+    source = texturedEffect->mTexture->AsSourceOGL();
+    // This is used by IOSurface that use 0,0...w,h coordinate rather then
+    // 0,0..1,1.
+    program->SetTexCoordMultiplier(source->GetSize().width,
+                                   source->GetSize().height);
+  }
+
+  // XXX kip - These calculations could be performed once per layer rather than
+  //           for every tile.  This might belong in Compositor.cpp once DEAA
+  //           is implemented for DirectX.
+  if (bEnableAA) {
+    // Calculate the transformed vertices of aVisibleRect in screen space
+    // pixels, mirroring the calculations in the vertex shader
+    Matrix4x4 flatTransform = aTransform;
+    flatTransform.PostTranslate(-offset.x, -offset.y, 0.0f);
+    flatTransform *= mProjMatrix;
+
+    Rect viewportClip = Rect(-1.0f, -1.0f, 2.0f, 2.0f);
+    size_t edgeCount = 0;
+    Point3D coefficients[4];
+
+    Point points[Matrix4x4::kTransformAndClipRectMaxVerts];
+    size_t pointCount =
+        flatTransform.TransformAndClipRect(aVisibleRect, viewportClip, points);
+    for (size_t i = 0; i < pointCount; i++) {
+      points[i] = Point((points[i].x * 0.5f + 0.5f) * mViewportSize.width,
+                        (points[i].y * 0.5f + 0.5f) * mViewportSize.height);
+    }
+    if (pointCount > 2) {
+      // Use shoelace formula on a triangle in the clipped quad to determine if
+      // winding order is reversed.  Iterate through the triangles until one is
+      // found with a non-zero area.
+      float winding = 0.0f;
+      size_t wp = 0;
+      while (winding == 0.0f && wp < pointCount) {
+        int wp1 = (wp + 1) % pointCount;
+        int wp2 = (wp + 2) % pointCount;
+        winding = (points[wp1].x - points[wp].x).value *
+                      (points[wp1].y + points[wp].y).value +
+                  (points[wp2].x - points[wp1].x).value *
+                      (points[wp2].y + points[wp1].y).value +
+                  (points[wp].x - points[wp2].x).value *
+                      (points[wp].y + points[wp2].y).value;
+        wp++;
+      }
+      bool frontFacing = winding >= 0.0f;
+
+      // Calculate the line coefficients used by the DEAA shader to determine
+      // the sub-pixel coverage of the edge pixels
+      for (size_t i = 0; i < pointCount; i++) {
+        const Point& p1 = points[i];
+        const Point& p2 = points[(i + 1) % pointCount];
+        // Create a DEAA edge for any non-straight lines, to a maximum of 4
+        if (p1.x != p2.x && p1.y != p2.y && edgeCount < 4) {
+          if (frontFacing) {
+            coefficients[edgeCount++] = GetLineCoefficients(p2, p1);
+          } else {
+            coefficients[edgeCount++] = GetLineCoefficients(p1, p2);
+          }
+        }
+      }
+    }
+
+    // The coefficients that are not needed must not cull any fragments.
+    // We fill these unused coefficients with a clipping plane that has no
+    // effect.
+    for (size_t i = edgeCount; i < 4; i++) {
+      coefficients[i] = Point3D(0.0f, 1.0f, mViewportSize.height);
+    }
+
+    // Set uniforms required by DEAA shader
+    Matrix4x4 transformInverted = aTransform;
+    transformInverted.Invert();
+    program->SetLayerTransformInverse(transformInverted);
+    program->SetDEAAEdges(coefficients);
+    program->SetVisibleCenter(aVisibleRect.Center());
+    program->SetViewportSize(mViewportSize);
+  }
+
+  bool didSetBlendMode = false;
+
+  switch (aEffectChain.mPrimaryEffect->mType) {
+    case EffectTypes::RGB: {
+      TexturedEffect* texturedEffect =
+          static_cast<TexturedEffect*>(aEffectChain.mPrimaryEffect.get());
+      TextureSource* source = texturedEffect->mTexture;
+
+      didSetBlendMode = SetBlendMode(gl(), gfx::CompositionOp::OP_OVER,
+                                     texturedEffect->mPremultiplied);
+
+      gfx::SamplingFilter samplingFilter = texturedEffect->mSamplingFilter;
+
+      source->AsSourceOGL()->BindTexture(LOCAL_GL_TEXTURE0, samplingFilter);
+
+      program->SetTextureUnit(0);
+
+      Matrix4x4 textureTransform = source->AsSourceOGL()->GetTextureTransform();
+      program->SetTextureTransform(textureTransform);
+
+      BindAndDrawGeometryWithTextureRect(
+          program, aGeometry, texturedEffect->mTextureCoords, source);
+      source->AsSourceOGL()->MaybeFenceTexture();
+    } break;
+    case EffectTypes::YCBCR: {
+      EffectYCbCr* effectYCbCr =
+          static_cast<EffectYCbCr*>(aEffectChain.mPrimaryEffect.get());
+      TextureSource* sourceYCbCr = effectYCbCr->mTexture;
+      const int Y = 0, Cb = 1, Cr = 2;
+      TextureSourceOGL* sourceY = sourceYCbCr->GetSubSource(Y)->AsSourceOGL();
+      TextureSourceOGL* sourceCb = sourceYCbCr->GetSubSource(Cb)->AsSourceOGL();
+      TextureSourceOGL* sourceCr = sourceYCbCr->GetSubSource(Cr)->AsSourceOGL();
+
+      if (!sourceY || !sourceCb || !sourceCr) {
+        NS_WARNING("Invalid layer texture.");
+        return;
+      }
+
+      sourceY->BindTexture(LOCAL_GL_TEXTURE0, effectYCbCr->mSamplingFilter);
+      sourceCb->BindTexture(LOCAL_GL_TEXTURE1, effectYCbCr->mSamplingFilter);
+      sourceCr->BindTexture(LOCAL_GL_TEXTURE2, effectYCbCr->mSamplingFilter);
+
+      if (config.mFeatures & ENABLE_TEXTURE_RECT) {
+        // This is used by IOSurface that use 0,0...w,h coordinate rather then
+        // 0,0..1,1.
+        program->SetCbCrTexCoordMultiplier(sourceCb->GetSize().width,
+                                           sourceCb->GetSize().height);
+      }
+
+      program->SetYCbCrTextureUnits(Y, Cb, Cr);
+      program->SetTextureTransform(Matrix4x4());
+      program->SetYUVColorSpace(effectYCbCr->mYUVColorSpace);
+
+      BindAndDrawGeometryWithTextureRect(program, aGeometry,
+                                         effectYCbCr->mTextureCoords,
+                                         sourceYCbCr->GetSubSource(Y));
+      sourceY->MaybeFenceTexture();
+      sourceCb->MaybeFenceTexture();
+      sourceCr->MaybeFenceTexture();
+    } break;
+    case EffectTypes::NV12: {
+      EffectNV12* effectNV12 =
+          static_cast<EffectNV12*>(aEffectChain.mPrimaryEffect.get());
+      TextureSource* sourceNV12 = effectNV12->mTexture;
+      const int Y = 0, CbCr = 1;
+      TextureSourceOGL* sourceY = sourceNV12->GetSubSource(Y)->AsSourceOGL();
+      TextureSourceOGL* sourceCbCr =
+          sourceNV12->GetSubSource(CbCr)->AsSourceOGL();
+
+      if (!sourceY || !sourceCbCr) {
+        NS_WARNING("Invalid layer texture.");
+        return;
+      }
+
+      sourceY->BindTexture(LOCAL_GL_TEXTURE0, effectNV12->mSamplingFilter);
+      sourceCbCr->BindTexture(LOCAL_GL_TEXTURE1, effectNV12->mSamplingFilter);
+
+      if (config.mFeatures & ENABLE_TEXTURE_RECT) {
+        // This is used by IOSurface that use 0,0...w,h coordinate rather then
+        // 0,0..1,1.
+        program->SetCbCrTexCoordMultiplier(sourceCbCr->GetSize().width,
+                                           sourceCbCr->GetSize().height);
+      }
+
+      program->SetNV12TextureUnits(Y, CbCr);
+      program->SetTextureTransform(Matrix4x4());
+      program->SetYUVColorSpace(effectNV12->mYUVColorSpace);
+
+      BindAndDrawGeometryWithTextureRect(program, aGeometry,
+                                         effectNV12->mTextureCoords,
+                                         sourceNV12->GetSubSource(Y));
+      sourceY->MaybeFenceTexture();
+      sourceCbCr->MaybeFenceTexture();
+    } break;
+    default:
+      MOZ_ASSERT(false, "Unhandled effect type");
+      break;
+  }
+
+  if (didSetBlendMode) {
+    gl()->fBlendFuncSeparate(LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA,
+                             LOCAL_GL_ONE, LOCAL_GL_ONE_MINUS_SRC_ALPHA);
+  }
+
+  // in case rendering has used some other GL context
+  MakeCurrent();
+}
+
+void CompositorOGL::BindAndDrawGeometry(ShaderProgramOGL* aProgram,
+                                        const gfx::Rect& aRect) {
+  BindAndDrawQuad(aProgram, aRect);
+}
+
+void CompositorOGL::BindAndDrawGeometry(
+    ShaderProgramOGL* aProgram,
+    const nsTArray<gfx::TexturedTriangle>& aTriangles) {
+  NS_ASSERTION(aProgram->HasInitialized(),
+               "Shader program not correctly initialized");
+
+  const nsTArray<TexturedVertex> vertices =
+      TexturedTrianglesToVertexArray(aTriangles);
+
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mTriangleVBO);
+  mGLContext->fBufferData(LOCAL_GL_ARRAY_BUFFER,
+                          vertices.Length() * sizeof(TexturedVertex),
+                          vertices.Elements(), LOCAL_GL_STREAM_DRAW);
+
+  const GLsizei stride = 4 * sizeof(GLfloat);
+  InitializeVAO(kCoordinateAttributeIndex, 2, stride, 0);
+  InitializeVAO(kTexCoordinateAttributeIndex, 2, stride, 2 * sizeof(GLfloat));
+
+  mGLContext->fDrawArrays(LOCAL_GL_TRIANGLES, 0, vertices.Length());
+
+  mGLContext->fDisableVertexAttribArray(kCoordinateAttributeIndex);
+  mGLContext->fDisableVertexAttribArray(kTexCoordinateAttributeIndex);
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+}
+
+// |aRect| is the rectangle we want to draw to. We will draw it with
+// up to 4 draw commands if necessary to avoid wrapping.
+// |aTexCoordRect| is the rectangle from the texture that we want to
+// draw using the given program.
+// |aTexture| is the texture we are drawing. Its actual size can be
+// larger than the rectangle given by |texCoordRect|.
+void CompositorOGL::BindAndDrawGeometryWithTextureRect(
+    ShaderProgramOGL* aProg, const Rect& aRect, const Rect& aTexCoordRect,
+    TextureSource* aTexture) {
+  Rect scaledTexCoordRect = GetTextureCoordinates(aTexCoordRect, aTexture);
+  Rect layerRects[4];
+  Rect textureRects[4];
+  size_t rects = DecomposeIntoNoRepeatRects(aRect, scaledTexCoordRect,
+                                            &layerRects, &textureRects);
+
+  BindAndDrawQuads(aProg, rects, layerRects, textureRects);
+}
+
+void CompositorOGL::BindAndDrawGeometryWithTextureRect(
+    ShaderProgramOGL* aProg, const nsTArray<gfx::TexturedTriangle>& aTriangles,
+    const gfx::Rect& aTexCoordRect, TextureSource* aTexture) {
+  BindAndDrawGeometry(aProg, aTriangles);
+}
+
+void CompositorOGL::BindAndDrawQuads(ShaderProgramOGL* aProg, int aQuads,
+                                     const Rect* aLayerRects,
+                                     const Rect* aTextureRects) {
+  NS_ASSERTION(aProg->HasInitialized(),
+               "Shader program not correctly initialized");
+
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mQuadVBO);
+  InitializeVAO(kCoordinateAttributeIndex, 4, 0, 0);
+
+  aProg->SetLayerRects(aLayerRects);
+  if (aProg->GetTextureCount() > 0) {
+    aProg->SetTextureRects(aTextureRects);
+  }
+
+  // We are using GL_TRIANGLES here because the Mac Intel drivers fail to
+  // properly process uniform arrays with GL_TRIANGLE_STRIP. Go figure.
+  mGLContext->fDrawArrays(LOCAL_GL_TRIANGLES, 0, 6 * aQuads);
+  mGLContext->fDisableVertexAttribArray(kCoordinateAttributeIndex);
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+}
+
+void CompositorOGL::InitializeVAO(const GLuint aAttrib, const GLint aComponents,
+                                  const GLsizei aStride, const size_t aOffset) {
+  mGLContext->fVertexAttribPointer(aAttrib, aComponents, LOCAL_GL_FLOAT,
+                                   LOCAL_GL_FALSE, aStride,
+                                   reinterpret_cast<GLvoid*>(aOffset));
+  mGLContext->fEnableVertexAttribArray(aAttrib);
+}
+
+#ifdef MOZ_DUMP_PAINTING
+template <typename T>
+void WriteSnapshotToDumpFile_internal(T* aObj, DataSourceSurface* aSurf) {
+  nsCString string(aObj->Name());
+  string.Append('-');
+  string.AppendInt((uint64_t)aObj);
+  if (gfxUtils::sDumpPaintFile != stderr) {
+    fprintf_stderr(gfxUtils::sDumpPaintFile, R"(array["%s"]=")",
+                   string.BeginReading());
+  }
+  gfxUtils::DumpAsDataURI(aSurf, gfxUtils::sDumpPaintFile);
+  if (gfxUtils::sDumpPaintFile != stderr) {
+    fprintf_stderr(gfxUtils::sDumpPaintFile, R"(";)");
+  }
+}
+
+void WriteSnapshotToDumpFile(Compositor* aCompositor, DrawTarget* aTarget) {
+  RefPtr<SourceSurface> surf = aTarget->Snapshot();
+  RefPtr<DataSourceSurface> dSurf = surf->GetDataSurface();
+  WriteSnapshotToDumpFile_internal(aCompositor, dSurf);
+}
+#endif
+
+void CompositorOGL::EndFrame() {
+  AUTO_PROFILER_LABEL("CompositorOGL::EndFrame", GRAPHICS);
+
+#ifdef MOZ_DUMP_PAINTING
+  if (gfxEnv::MOZ_DISABLE_FORCE_PRESENT()) {
+    LayoutDeviceIntSize size;
+    if (mUseExternalSurfaceSize) {
+      size = LayoutDeviceIntSize(mSurfaceSize.width, mSurfaceSize.height);
+    } else {
+      size = mWidget->GetClientSize();
+    }
+    RefPtr<DrawTarget> target =
+        gfxPlatform::GetPlatform()->CreateOffscreenContentDrawTarget(
+            IntSize(size.width, size.height), SurfaceFormat::B8G8R8A8);
+    if (target) {
+      CopyToTarget(target, nsIntPoint(), Matrix());
+      WriteSnapshotToDumpFile(this, target);
+    }
+  }
+#endif
+
+  mFrameInProgress = false;
+  mShouldInvalidateWindow = false;
+
+  if (mTarget) {
+    CopyToTarget(mTarget, mTargetBounds.TopLeft(), Matrix());
+    mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+    mTarget = nullptr;
+    mWindowRenderTarget = nullptr;
+    mCurrentRenderTarget = nullptr;
+    Compositor::EndFrame();
+    return;
+  }
+
+  mWindowRenderTarget = nullptr;
+  mCurrentRenderTarget = nullptr;
+
+  if (mTexturePool) {
+    mTexturePool->EndFrame();
+  }
+
+  InsertFrameDoneSync();
+
+  mGLContext->SetDamage(mCurrentFrameInvalidRegion);
+  mGLContext->SwapBuffers();
+  mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+
+  // Unbind all textures
+  for (GLuint i = 0; i <= 4; i++) {
+    mGLContext->fActiveTexture(LOCAL_GL_TEXTURE0 + i);
+    mGLContext->fBindTexture(LOCAL_GL_TEXTURE_2D, 0);
+    if (!mGLContext->IsGLES()) {
+      mGLContext->fBindTexture(LOCAL_GL_TEXTURE_RECTANGLE_ARB, 0);
+    }
+  }
+
+  mCurrentFrameInvalidRegion.SetEmpty();
+
+  Compositor::EndFrame();
+}
+
+void CompositorOGL::InsertFrameDoneSync() {
+#ifdef XP_MACOSX
+  // Only do this on macOS.
+  // On other platforms, SwapBuffers automatically applies back-pressure.
+  if (mThisFrameDoneSync) {
+    mGLContext->fDeleteSync(mThisFrameDoneSync);
+  }
+  mThisFrameDoneSync =
+      mGLContext->fFenceSync(LOCAL_GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+#elif defined(MOZ_WIDGET_ANDROID)
+  const auto& gle = gl::GLContextEGL::Cast(mGLContext);
+  const auto& egl = gle->mEgl;
+
+  EGLSync sync = nullptr;
+  if (AndroidHardwareBufferApi::Get()) {
+    sync = egl->fCreateSync(LOCAL_EGL_SYNC_NATIVE_FENCE_ANDROID, nullptr);
+  }
+  if (sync) {
+    int fenceFd = egl->fDupNativeFenceFDANDROID(sync);
+    if (fenceFd >= 0) {
+      mReleaseFenceFd = ipc::FileDescriptor(UniqueFileHandle(fenceFd));
+    }
+    egl->fDestroySync(sync);
+    sync = nullptr;
+  }
+#endif
+}
+
+ipc::FileDescriptor CompositorOGL::GetReleaseFence() { return mReleaseFenceFd; }
+
+bool CompositorOGL::NeedToRecreateFullWindowRenderTarget() const {
+  if (!ShouldRecordFrames()) {
+    return false;
+  }
+  if (!mFullWindowRenderTarget) {
+    return true;
+  }
+  IntSize windowSize = mWidget->GetClientSize().ToUnknownSize();
+  return mFullWindowRenderTarget->GetSize() != windowSize;
+}
+
+void CompositorOGL::SetDestinationSurfaceSize(const IntSize& aSize) {
+  mSurfaceSize.width = aSize.width;
+  mSurfaceSize.height = aSize.height;
+}
+
+void CompositorOGL::CopyToTarget(DrawTarget* aTarget,
+                                 const nsIntPoint& aTopLeft,
+                                 const gfx::Matrix& aTransform) {
+  MOZ_ASSERT(aTarget);
+  IntRect rect;
+  if (mUseExternalSurfaceSize) {
+    rect = IntRect(0, 0, mSurfaceSize.width, mSurfaceSize.height);
+  } else {
+    rect = IntRect(0, 0, mWidgetSize.width, mWidgetSize.height);
+  }
+  GLint width = rect.Width();
+  GLint height = rect.Height();
+
+  if ((int64_t(width) * int64_t(height) * int64_t(4)) > INT32_MAX) {
+    NS_ERROR("Widget size too big - integer overflow!");
+    return;
+  }
+
+  RefPtr<DataSourceSurface> source = Factory::CreateDataSourceSurface(
+      rect.Size(), gfx::SurfaceFormat::B8G8R8A8);
+  if (NS_WARN_IF(!source)) {
+    return;
+  }
+
+  ReadPixelsIntoDataSurface(mGLContext, source);
+
+  // Map from GL space to Cairo space and reverse the world transform.
+  Matrix glToCairoTransform = aTransform;
+  glToCairoTransform.Invert();
+  glToCairoTransform.PreScale(1.0, -1.0);
+  glToCairoTransform.PreTranslate(0.0, -height);
+
+  glToCairoTransform.PostTranslate(-aTopLeft.x, -aTopLeft.y);
+
+  Matrix oldMatrix = aTarget->GetTransform();
+  aTarget->SetTransform(glToCairoTransform);
+  Rect floatRect = Rect(rect.X(), rect.Y(), width, height);
+  aTarget->DrawSurface(source, floatRect, floatRect, DrawSurfaceOptions(),
+                       DrawOptions(1.0f, CompositionOp::OP_SOURCE));
+  aTarget->SetTransform(oldMatrix);
+  aTarget->Flush();
+}
+
+void CompositorOGL::Pause() {
+#ifdef MOZ_WIDGET_ANDROID
+  if (!gl() || gl()->IsDestroyed()) return;
+  // ReleaseSurface internally calls MakeCurrent
+  gl()->ReleaseSurface();
+#elif defined(MOZ_WAYLAND)
+  // ReleaseSurface internally calls MakeCurrent
+  gl()->ReleaseSurface();
+#endif
+}
+
+bool CompositorOGL::Resume() {
+#if defined(MOZ_WIDGET_ANDROID) || defined(MOZ_WIDGET_UIKIT) || \
+    defined(MOZ_WAYLAND)
+  if (!gl() || gl()->IsDestroyed()) return false;
+
+  // RenewSurface internally calls MakeCurrent.
+  return gl()->RenewSurface(GetWidget());
+#else
+  return true;
+#endif
+}
+
+already_AddRefed<DataTextureSource> CompositorOGL::CreateDataTextureSource(
+    TextureFlags aFlags) {
+  if (!gl()) {
+    return nullptr;
+  }
+
+  return MakeAndAddRef<TextureImageTextureSourceOGL>(this, aFlags);
+}
+
+int32_t CompositorOGL::GetMaxTextureSize() const {
+  MOZ_ASSERT(mGLContext);
+  GLint texSize = 0;
+  mGLContext->fGetIntegerv(LOCAL_GL_MAX_TEXTURE_SIZE, &texSize);
+  MOZ_ASSERT(texSize != 0);
+  return texSize;
+}
+
+void CompositorOGL::MakeCurrent(MakeCurrentFlags aFlags) {
+  if (mDestroyed) {
+    NS_WARNING("Call on destroyed layer manager");
+    return;
+  }
+  mGLContext->MakeCurrent(aFlags & ForceMakeCurrent);
+}
+
+GLuint CompositorOGL::GetTemporaryTexture(GLenum aTarget, GLenum aUnit) {
+  if (!mTexturePool) {
+    mTexturePool = new PerUnitTexturePoolOGL(gl());
+  }
+  return mTexturePool->GetTexture(aTarget, aUnit);
+}
+
+GLuint PerUnitTexturePoolOGL::GetTexture(GLenum aTarget, GLenum aTextureUnit) {
+  if (mTextureTarget == 0) {
+    mTextureTarget = aTarget;
+  }
+  MOZ_ASSERT(mTextureTarget == aTarget);
+
+  size_t index = aTextureUnit - LOCAL_GL_TEXTURE0;
+  // lazily grow the array of temporary textures
+  if (mTextures.Length() <= index) {
+    size_t prevLength = mTextures.Length();
+    mTextures.SetLength(index + 1);
+    for (unsigned int i = prevLength; i <= index; ++i) {
+      mTextures[i] = 0;
+    }
+  }
+  // lazily initialize the temporary textures
+  if (!mTextures[index]) {
+    if (!mGL->MakeCurrent()) {
+      return 0;
+    }
+    mGL->fGenTextures(1, &mTextures[index]);
+    mGL->fBindTexture(aTarget, mTextures[index]);
+    mGL->fTexParameteri(aTarget, LOCAL_GL_TEXTURE_WRAP_S,
+                        LOCAL_GL_CLAMP_TO_EDGE);
+    mGL->fTexParameteri(aTarget, LOCAL_GL_TEXTURE_WRAP_T,
+                        LOCAL_GL_CLAMP_TO_EDGE);
+  }
+  return mTextures[index];
+}
+
+void PerUnitTexturePoolOGL::DestroyTextures() {
+  if (mGL && mGL->MakeCurrent()) {
+    if (mTextures.Length() > 0) {
+      mGL->fDeleteTextures(mTextures.Length(), &mTextures[0]);
+    }
+  }
+  mTextures.SetLength(0);
+}
+
+void CompositorOGL::RegisterTextureSource(TextureSource* aTextureSource) {
+#ifdef MOZ_WIDGET_GTK
+  if (mDestroyed) {
+    return;
+  }
+  mRegisteredTextureSources.insert(aTextureSource);
+#endif
+}
+
+void CompositorOGL::UnregisterTextureSource(TextureSource* aTextureSource) {
+#ifdef MOZ_WIDGET_GTK
+  if (mDestroyed) {
+    return;
+  }
+  mRegisteredTextureSources.erase(aTextureSource);
+#endif
+}
+
+}  // namespace layers
+}  // namespace mozilla