[WIP] cc: Use sRGB for rastering non-wide-color-gamut content

cc/raster/raster_source.h

Index: cc/raster/raster_source.h
diff --git a/cc/raster/raster_source.h b/cc/raster/raster_source.h
index df899ab220c7d9a11768edb59d491e6dd16342b4..14ecf8b1617446270b6f24db15c5470d08a8b7c6 100644
--- a/cc/raster/raster_source.h
+++ b/cc/raster/raster_source.h
@@ -93,6 +93,10 @@ class CC_EXPORT RasterSource : public base::RefCountedThreadSafe<RasterSource> {
                                  float contents_scale,
                                  SkColor* color) const;
 
+  // Returns true iff there exists content in the raster source that was not
+  // originally specified in SRGB color space.
+  bool HasNonSRGBContent() const;
+
   // Returns true iff the whole raster source is of solid color.
   bool IsSolidColor() const;