cc: Add checker-imaging support to TileManager.

cc/playback/image_hijack_canvas.h

Index: cc/playback/image_hijack_canvas.h
diff --git a/cc/playback/image_hijack_canvas.h b/cc/playback/image_hijack_canvas.h
index be9a6ba9c3a5527ed928a89864305e0a3021c511..e828f5611f61f2ca9b24ec8d41bed370c3976a08 100644
--- a/cc/playback/image_hijack_canvas.h
+++ b/cc/playback/image_hijack_canvas.h
@@ -5,8 +5,11 @@
 #ifndef CC_PLAYBACK_IMAGE_HIJACK_CANVAS_H_
 #define CC_PLAYBACK_IMAGE_HIJACK_CANVAS_H_
 
+#include <unordered_set>
+
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
+#include "cc/playback/image_id.h"
 #include "third_party/skia/include/utils/SkNWayCanvas.h"
 
 namespace cc {
@@ -17,7 +20,8 @@ class CC_EXPORT ImageHijackCanvas : public SkNWayCanvas {
  public:
   ImageHijackCanvas(int width,
                     int height,
-                    ImageDecodeCache* image_decode_cache);
+                    ImageDecodeCache* image_decode_cache,
+                    const std::unordered_set<ImageId>* images_to_skip);

[vmpstr, 2017/02/10 19:25:42]

maybe use base::flat_set here? Or vector? I feel like whenever we use an
unordered set, we kind of want justification for why that's better over vector

Realistically, this will be empty for a lot of cases and very small when it's
not empty.

[Khushal, 2017/02/10 22:09:19]

Done. So other cases where we have sets are in CheckerImageTracker. I think the
images_decoded_once_ should definitely remain a set. Do you have an opinion
about the rest there?

 
  private:
   // Ensure that pictures are unpacked by this canvas, instead of being
@@ -48,7 +52,10 @@ class CC_EXPORT ImageHijackCanvas : public SkNWayCanvas {
                        const SkRect& dst,
                        const SkPaint* paint) override;
 
+  bool ShouldSkipImage(const SkImage* image);
+
   ImageDecodeCache* image_decode_cache_;
+  const std::unordered_set<ImageId>* images_to_skip_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageHijackCanvas);
 };