Revert of 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 3585a7e781c60245f8d5f40781220c9c45d1564d..6cb3b190b2deb55c6bcbf0b1bcb198992c9fb014 100644
--- a/cc/test/fake_display_list_recording_source.h
+++ b/cc/test/fake_display_list_recording_source.h
@@ -95,9 +95,7 @@
   }
 
   bool IsSuitableForGpuRasterization() const override;
-  void SetUnsuitableForGpuRasterization() {
-    force_unsuitable_for_gpu_rasterization_ = true;
-  }
+  void SetUnsuitableForGpuRasterizationForTesting() override;
 
  private:
   FakeContentLayerClient client_;