Add explicit flush after copyTextureCHROMIUM to make the change visible accross contexts.

content/renderer/media/webmediaplayer_impl.cc

Index: content/renderer/media/webmediaplayer_impl.cc
diff --git a/content/renderer/media/webmediaplayer_impl.cc b/content/renderer/media/webmediaplayer_impl.cc
index 9399476dd837e07a3435c0bdfebf7ced6fb91742..b3ea6def86b7322c9f0c55bbc92ea6a0accea502 100644
--- a/content/renderer/media/webmediaplayer_impl.cc
+++ b/content/renderer/media/webmediaplayer_impl.cc
@@ -680,9 +680,6 @@ bool WebMediaPlayerImpl::copyVideoTextureToPlatformTexture(
   web_graphics_context->bindTexture(GL_TEXTURE_2D, texture);
 
   web_graphics_context->deleteTexture(source_texture);
-
-  // The flush() operation is not necessary here. It is kept since the
-  // performance will be better when it is added than not.
   web_graphics_context->flush();
   return true;
 }