Make stream captures work on canvases that are not in the DOM.

third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp

Index: third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp b/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
index bb9cfa9e6d32867abdcbf4541e2a9eb8da4377f9..d690aad946af21ce539d3fca205646ba381569f4 100644
--- a/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
+++ b/third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.cpp
@@ -846,9 +846,9 @@ bool Canvas2DLayerBridge::checkSurfaceValid() {
 
 bool Canvas2DLayerBridge::restoreSurface() {
   DCHECK(!m_destructionInProgress);
-  if (m_destructionInProgress)
+  if (m_destructionInProgress || !isAccelerated())

[xlai (Olivia), 2017/01/27 22:23:25]

Why is this change related to the decoupling of finalizeFrame and
paintInvalidation?

[Justin Novosad, 2017/02/07 21:52:29]

I was getting DCHECK failures below in some of the unit tests.  It is because
the order of surface restoration has changed with respect to finalizeFrame, and
isAccelerated() is a bit wonky when the context is still lost.

     return false;
-  DCHECK(isAccelerated() && !m_surface);
+  DCHECK(!m_surface);
 
   gpu::gles2::GLES2Interface* sharedGL = nullptr;
   m_layer->clearTexture();
@@ -918,12 +918,6 @@ bool Canvas2DLayerBridge::PrepareTextureMailbox(
     // 4. Here.
     return false;
   }
-  DCHECK(isAccelerated() || isHibernating() || m_softwareRenderingWhileHidden);
-
-  // if hibernating but not hidden, we want to wake up from
-  // hibernation
-  if ((isHibernating() || m_softwareRenderingWhileHidden) && isHidden())
-    return false;
 
   // If the context is lost, we don't know if we should be producing GPU or
   // software frames, until we get a new context, since the compositor will
@@ -933,6 +927,13 @@ bool Canvas2DLayerBridge::PrepareTextureMailbox(
           GL_NO_ERROR)
     return false;
 
+  DCHECK(isAccelerated() || isHibernating() || m_softwareRenderingWhileHidden);

[xlai (Olivia), 2017/01/27 22:23:25]

Same question.

[Justin Novosad, 2017/02/07 21:52:29]

Same answer.

+
+  // if hibernating but not hidden, we want to wake up from
+  // hibernation
+  if ((isHibernating() || m_softwareRenderingWhileHidden) && isHidden())
+    return false;
+
   sk_sp<SkImage> image =
       newImageSnapshot(PreferAcceleration, SnapshotReasonUnknown);
   if (!image || !image->getTexture())
@@ -1062,17 +1063,22 @@ void Canvas2DLayerBridge::didDraw(const FloatRect& rect) {
   m_didDrawSinceLastGpuFlush = true;
 }
 
-void Canvas2DLayerBridge::prepareSurfaceForPaintingIfNeeded() {
+void Canvas2DLayerBridge::finalizeFrame() {
+  DCHECK(!m_destructionInProgress);
+
+  // Make sure surface is ready for painting: fix the rendering mode now
+  // because it will be too late during the paint invalidation phase.
   getOrCreateSurface(PreferAcceleration);
+
+  if (m_rateLimiter)
+    m_rateLimiter->reset();
+  m_renderingTaskCompletedForCurrentFrame = false;
 }
 
-void Canvas2DLayerBridge::finalizeFrame(const FloatRect& dirtyRect) {
+void Canvas2DLayerBridge::doPaintInvalidation(const FloatRect& dirtyRect) {
   DCHECK(!m_destructionInProgress);
   if (m_layer && m_accelerationMode != DisableAcceleration)
     m_layer->layer()->invalidateRect(enclosingIntRect(dirtyRect));
-  if (m_rateLimiter)
-    m_rateLimiter->reset();
-  m_renderingTaskCompletedForCurrentFrame = false;
 }
 
 void Canvas2DLayerBridge::didProcessTask() {