Implements core logic for Pixel Canvas

ui/compositor/compositor_switches.h

Index: ui/compositor/compositor_switches.h
diff --git a/ui/compositor/compositor_switches.h b/ui/compositor/compositor_switches.h
index 0cc31be97b383808b4bf3797a3961ffc7d2b0c1f..54a9dcf76c6b060acb2f7df856bfe039d361d3d0 100644
--- a/ui/compositor/compositor_switches.h
+++ b/ui/compositor/compositor_switches.h
@@ -16,6 +16,7 @@ COMPOSITOR_EXPORT extern const char kUIEnableRGBA4444Textures[];
 COMPOSITOR_EXPORT extern const char kUIEnableZeroCopy[];
 COMPOSITOR_EXPORT extern const char kUIShowPaintRects[];
 COMPOSITOR_EXPORT extern const char kUISlowAnimations[];
+COMPOSITOR_EXPORT extern const char kEnablePixelCanvasRecording[];
 
 }  // namespace switches
 
@@ -23,6 +24,9 @@ namespace ui {
 
 bool IsUIZeroCopyEnabled();
 
+bool IsPixelCanvasRecordingEnabled();
+COMPOSITOR_EXPORT void SetPixelCanvasForTesting(bool value);
+
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_SWITCHES_H_