Update from https://crrev.com/306655

cc/resources/raster_source.h

Index: cc/resources/raster_source.h
diff --git a/cc/resources/raster_source.h b/cc/resources/raster_source.h
index 3584436469571604f463766d88ff9060c71a132b..88c996214b8e1d9b5ec05e23a05b73554302d5d6 100644
--- a/cc/resources/raster_source.h
+++ b/cc/resources/raster_source.h
@@ -18,6 +18,8 @@ class SkPicture;
 
 namespace cc {
 
+class Picture;
+
 class CC_EXPORT RasterSource : public base::RefCountedThreadSafe<RasterSource> {
  public:
   struct CC_EXPORT SolidColorAnalysis {
@@ -92,6 +94,7 @@ class CC_EXPORT RasterSource : public base::RefCountedThreadSafe<RasterSource> {
   virtual void DidBeginTracing() = 0;
   virtual void AsValueInto(base::debug::TracedValue* array) const = 0;
   virtual skia::RefPtr<SkPicture> GetFlattenedPicture() = 0;
+  virtual size_t GetPictureMemoryUsage() const = 0;
 
   // Return true if LCD anti-aliasing may be used when rastering text.
   virtual bool CanUseLCDText() const = 0;