cc: Add image decode queue functionality to image manager.

cc/test/fake_tile_manager.h

Index: cc/test/fake_tile_manager.h
diff --git a/cc/test/fake_tile_manager.h b/cc/test/fake_tile_manager.h
index 07380079502b283e99984d8a8d93af06588e1a6c..0e1d715b80ce42db2513166dab7b87612966d7d5 100644
--- a/cc/test/fake_tile_manager.h
+++ b/cc/test/fake_tile_manager.h
@@ -15,8 +15,8 @@ namespace cc {
 
 class FakeTileManager : public TileManager {
  public:
-  explicit FakeTileManager(TileManagerClient* client);
-  FakeTileManager(TileManagerClient* client, ResourcePool* resource_pool);
+  FakeTileManager(TileManagerClient* client,
+                  ResourcePool* resource_pool = nullptr);
   ~FakeTileManager() override;
 
   bool HasBeenAssignedMemory(Tile* tile);
@@ -27,6 +27,7 @@ class FakeTileManager : public TileManager {
 
  private:
   SoftwareImageDecodeCache image_decode_cache_;
+  DecodedImageTracker decoded_image_tracker_;
 };
 
 }  // namespace cc