Stop disabling force_compositing_mode for background RenderViews.

content/browser/renderer_host/render_view_host_delegate.h

Index: content/browser/renderer_host/render_view_host_delegate.h
diff --git a/content/browser/renderer_host/render_view_host_delegate.h b/content/browser/renderer_host/render_view_host_delegate.h
index 0e2ab50bd1852e05c43a7e6103d7fd43a7351df2..793ddbc168b9e0c595455fa1ba4135004ef5beb5 100644
--- a/content/browser/renderer_host/render_view_host_delegate.h
+++ b/content/browser/renderer_host/render_view_host_delegate.h
@@ -323,6 +323,9 @@ class CONTENT_EXPORT RenderViewHostDelegate {
   virtual SessionStorageNamespace* GetSessionStorageNamespace(
       SiteInstance* instance);
 
+  // Returns true if the RenderViewHost will never be visible.
+  virtual bool IsNeverVisible();
+
   // Returns the FrameTree the render view should use. Guaranteed to be constant
   // for the lifetime of the render view.
   //