Cache gpu suitability in DisplayItemList, remove SetUnsuitable...ForTesting

cc/playback/display_list_recording_source.h

Index: cc/playback/display_list_recording_source.h
diff --git a/cc/playback/display_list_recording_source.h b/cc/playback/display_list_recording_source.h
index 5824b103804d7ed03ce56296687dcf4e0ae4bf6d..912d9363a99cbdaa25774400785ba4406e630580 100644
--- a/cc/playback/display_list_recording_source.h
+++ b/cc/playback/display_list_recording_source.h
@@ -33,7 +33,6 @@ class CC_EXPORT DisplayListRecordingSource : public RecordingSource {
   void SetBackgroundColor(SkColor background_color) override;
   void SetRequiresClear(bool requires_clear) override;
   bool IsSuitableForGpuRasterization() const override;
-  void SetUnsuitableForGpuRasterizationForTesting() override;
   // Returns true if the new recorded viewport exposes enough new area to be
   // worth re-recording.
   static bool ExposesEnoughNewArea(
@@ -66,8 +65,6 @@ class CC_EXPORT DisplayListRecordingSource : public RecordingSource {
 
   void DetermineIfSolidColor();
 
-  bool is_suitable_for_gpu_rasterization_;
-
   DISALLOW_COPY_AND_ASSIGN(DisplayListRecordingSource);
 };