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

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

Index: third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp b/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
index fa041cb5911cff63d06650ef30ff2b5ca73536fa..2e38b192ed37b338fecca618ef940f34a33e00fa 100644
--- a/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
@@ -148,18 +148,12 @@ bool ImageBuffer::isSurfaceValid() const {
   return m_surface->isValid();
 }
 
-bool ImageBuffer::isDirty() {
-  return m_client ? m_client->isDirty() : false;
+void ImageBuffer::finalizeFrame() {
+  m_surface->finalizeFrame();
 }
 
-void ImageBuffer::didFinalizeFrame() {
-  if (m_client)
-    m_client->didFinalizeFrame();
-}
-
-void ImageBuffer::finalizeFrame(const FloatRect& dirtyRect) {
-  m_surface->finalizeFrame(dirtyRect);
-  didFinalizeFrame();
+void ImageBuffer::doPaintInvalidation(const FloatRect& dirtyRect) {
+  m_surface->doPaintInvalidation(dirtyRect);
 }
 
 bool ImageBuffer::restoreSurface() const {