Garcefully handle glCreateGpuMemoryBufferImageCHROMIUM failure.

media/renderers/video_overlay_factory.h

Index: media/renderers/video_overlay_factory.h
diff --git a/media/renderers/video_overlay_factory.h b/media/renderers/video_overlay_factory.h
index 552d59c01a0d52f17453cbbbb6792d5d739e4483..b8cc2c5d16eb4f0a8278f8fb25d21eaa0f025cc2 100644
--- a/media/renderers/video_overlay_factory.h
+++ b/media/renderers/video_overlay_factory.h
@@ -31,6 +31,8 @@ class MEDIA_EXPORT VideoOverlayFactory {
 
  private:
   class Texture;
+  Texture* GetTexture();
+
   ::media::GpuVideoAcceleratorFactories* gpu_factories_;
   std::unique_ptr<Texture> texture_;