Fix missing finalizeFrame barriers in WebGL animations

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1164 matching lines @@
       std::move(contextProvider), this, clampedCanvasSize(), premultipliedAlpha,
       wantAlphaChannel, wantDepthBuffer, wantStencilBuffer, wantAntialiasing,
       preserve, webGLVersion, chromiumImageUsage);
 }
 
 void WebGLRenderingContextBase::initializeNewContext() {
   ASSERT(!isContextLost());
   ASSERT(drawingBuffer());
 
   m_markedCanvasDirty = false;
+  m_animationFrameInProgress = false;
   m_activeTextureUnit = 0;
   m_packAlignment = 4;
   m_unpackAlignment = 4;
   m_unpackFlipY = false;
   m_unpackPremultiplyAlpha = false;
   m_unpackColorspaceConversion = GC3D_BROWSER_DEFAULT_WEBGL;
   m_boundArrayBuffer = nullptr;
   m_currentProgram = nullptr;
   m_framebufferBinding = nullptr;
   m_renderbufferBinding = nullptr;
@@ skipping 195 matching lines @@
   if (m_framebufferBinding || isContextLost())
     return;
 
   if (!drawingBuffer()->markContentsChanged() && m_markedCanvasDirty) {
     return;
   }
 
   if (!canvas())
     return;
 
-  LayoutBox* layoutBox = canvas()->layoutBox();
-  if (layoutBox && layoutBox->hasAcceleratedCompositing()) {
-    layoutBox->contentChanged(changeType);
-  }
-  if (!m_markedCanvasDirty) {
-    m_markedCanvasDirty = true;
+  m_markedCanvasDirty = true;

[xlai (Olivia), 2017/02/21 19:56:56]

Just a bit curious: does this m_markedCanvasDirty have overlapping usage as with
m_animationFrameInProgress?

+
+  if (!m_animationFrameInProgress) {
+    m_animationFrameInProgress = true;

[Justin Novosad, 2017/02/21 18:06:21]

I renamed this variable. I think it is more readable now. Used to be 
m_paintInvalidatedForCurrentFrame

+    LayoutBox* layoutBox = canvas()->layoutBox();
+    if (layoutBox && layoutBox->hasAcceleratedCompositing()) {
+      layoutBox->contentChanged(changeType);
+    }
     IntSize canvasSize = clampedCanvasSize();
     didDraw(SkIRect::MakeXYWH(0, 0, canvasSize.width(), canvasSize.height()));
   }
 }
 
+void WebGLRenderingContextBase::finalizeFrame() {
+  m_animationFrameInProgress = false;
+}
+
 void WebGLRenderingContextBase::onErrorMessage(const char* message,
                                                int32_t id) {
   if (m_synthesizedErrorsToConsole)
     printGLErrorToConsole(message);
   InspectorInstrumentation::didFireWebGLErrorOrWarning(canvas(), message);
 }
 
 void WebGLRenderingContextBase::notifyCanvasContextChanged() {
   if (!canvas())
     return;
@@ skipping 6383 matching lines @@
 
 void WebGLRenderingContextBase::getHTMLOrOffscreenCanvas(
     HTMLCanvasElementOrOffscreenCanvas& result) const {
   if (canvas())
     result.setHTMLCanvasElement(canvas());
   else
     result.setOffscreenCanvas(offscreenCanvas());
 }
 
 }  // namespace blink