Refactor BrowserViewRenderer to support page visibility

android_webview/browser/browser_view_renderer.h

Index: android_webview/browser/browser_view_renderer.h
diff --git a/android_webview/browser/browser_view_renderer.h b/android_webview/browser/browser_view_renderer.h
index 97737aa246ff2bc5f2d130bf20fef4a90b38d96d..bd6bfc899f5f60f2a24a24100a4a82e7dff937d4 100644
--- a/android_webview/browser/browser_view_renderer.h
+++ b/android_webview/browser/browser_view_renderer.h
@@ -93,6 +93,7 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
   gfx::Size size() const { return size_; }
   void ReleaseHardware();
 
+  bool IsClientVisible() const;
   void TrimMemory(const int level, const bool visible);
 
   // SynchronousCompositorClient overrides.
@@ -179,6 +180,7 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
   base::CancelableClosure post_fallback_tick_;
   base::CancelableClosure fallback_tick_fired_;
   bool fallback_tick_pending_;
+  bool disable_page_visibility_;
 
   gfx::Size size_;