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

cc/test/fake_display_list_recording_source.h

Index: cc/test/fake_display_list_recording_source.h
diff --git a/cc/test/fake_display_list_recording_source.h b/cc/test/fake_display_list_recording_source.h
index 6cb3b190b2deb55c6bcbf0b1bcb198992c9fb014..3585a7e781c60245f8d5f40781220c9c45d1564d 100644
--- a/cc/test/fake_display_list_recording_source.h
+++ b/cc/test/fake_display_list_recording_source.h
@@ -95,7 +95,9 @@ class FakeDisplayListRecordingSource : public DisplayListRecordingSource {
   }
 
   bool IsSuitableForGpuRasterization() const override;
-  void SetUnsuitableForGpuRasterizationForTesting() override;
+  void SetUnsuitableForGpuRasterization() {
+    force_unsuitable_for_gpu_rasterization_ = true;
+  }
 
  private:
   FakeContentLayerClient client_;