Update from chromium https://crrev.com/301725/

cc/resources/raster_source.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CC_RESOURCES_RASTER_SOURCE_H_
+#define CC_RESOURCES_RASTER_SOURCE_H_
+
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "cc/base/cc_export.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+class SkCanvas;
+
+namespace cc {
+
+class RenderingStatsInstrumentation;
+
+class CC_EXPORT RasterSource : public base::RefCountedThreadSafe<RasterSource> {
+ public:
+  struct CC_EXPORT SolidColorAnalysis {
+    SolidColorAnalysis()
+        : is_solid_color(false), solid_color(SK_ColorTRANSPARENT) {}
+    ~SolidColorAnalysis() {}
+
+    bool is_solid_color;
+    SkColor solid_color;
+  };
+
+  // Raster a subrect of this RasterSource into the given canvas. It is
+  // assumed that contents_scale has already been applied to this canvas.
+  // Writes the total number of pixels rasterized and the time spent
+  // rasterizing to the stats if the respective pointer is not nullptr.
+  // TODO(vmpstr): Remove RenderingStatsInstrumentation from the interface.
+  virtual void PlaybackToCanvas(
+      SkCanvas* canvas,
+      const gfx::Rect& canvas_rect,
+      float contents_scale,
+      RenderingStatsInstrumentation* rendering_stats_instrumentation) const = 0;
+
+  // Analyze to determine if the given rect at given scale is of solid color in
+  // this raster source.
+  virtual void PerformSolidColorAnalysis(
+      const gfx::Rect& content_rect,
+      float contents_scale,
+      SolidColorAnalysis* analysis,
+      RenderingStatsInstrumentation* rendering_stats_instrumentation) const = 0;
+
+  // Populate the given list with all SkPixelRefs that may overlap the given
+  // rect at given scale.
+  virtual void GatherPixelRefs(const gfx::Rect& content_rect,
+                               float contents_scale,
+                               std::vector<SkPixelRef*>* pixel_refs) const = 0;
+
+  // Return true iff this raster source can raster the given rect at given
+  // scale.
+  virtual bool CoversRect(const gfx::Rect& content_rect,
+                          float contents_scale) const = 0;
+
+  // Return true iff this raster source would benefit from using distance
+  // field text.
+  virtual bool SuitableForDistanceFieldText() const = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<RasterSource>;
+
+  RasterSource() {}
+  virtual ~RasterSource() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RasterSource);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_RASTER_SOURCE_H_