Turn off flushes and sharing for the android GLHelper context.

GLHelper doesn't rely on automatic flushes, that is a WebGL thing. And
we use mailboxes, so we don't need to be in a global share group with
the context.

R=sievers@chromium.org
BUG=584497

Review URL: https://codereview.chromium.org/1899393002

Cr-Commit-Position: refs/heads/master@{#388637}

content/browser/renderer_host/render_widget_host_view_android.cc

@@ -177,10 +177,8 @@ void GLHelperHolder::Initialize() {
   limits.max_transfer_buffer_size = std::min(
       3 * full_screen_texture_size_in_bytes, kDefaultMaxTransferBufferSize);
 
-  bool share_resources = true;
-  // TODO(danakj): This should be false probably, it is for the main thread
-  // context which is used for GLHelper.
-  bool automatic_flushes = true;
+  bool share_resources = false;
+  bool automatic_flushes = false;
   GURL url("chrome://gpu/RenderWidgetHostViewAndroid");
 
   std::unique_ptr<WebGraphicsContext3DCommandBufferImpl> context(