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

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

Index: third_party/WebKit/Source/platform/graphics/ImageBuffer.h
diff --git a/third_party/WebKit/Source/platform/graphics/ImageBuffer.h b/third_party/WebKit/Source/platform/graphics/ImageBuffer.h
index 2c981fe4643d1c5023702a819f9f1442ba016dc2..ec8c83d7384a5e0ba13adccf9def5ccacf8bde8c 100644
--- a/third_party/WebKit/Source/platform/graphics/ImageBuffer.h
+++ b/third_party/WebKit/Source/platform/graphics/ImageBuffer.h
@@ -115,10 +115,8 @@ class PLATFORM_EXPORT ImageBuffer {
   void disableDeferral(DisableDeferralReason) const;
 
   // Called at the end of a task that rendered a whole frame
-  void finalizeFrame(const FloatRect& dirtyRect);
-  void didFinalizeFrame();
-
-  bool isDirty();
+  void finalizeFrame();
+  void doPaintInvalidation(const FloatRect& dirtyRect);
 
   bool writePixels(const SkImageInfo&,
                    const void* pixels,