Rewire Android WebView's compositor changed signal.

android_webview/native/aw_contents.h

Index: android_webview/native/aw_contents.h
diff --git a/android_webview/native/aw_contents.h b/android_webview/native/aw_contents.h
index 5062eb88ea5f34f303be2608d210a26ae8def30f..638aed53fc89c660c28966f73748839139426f0b 100644
--- a/android_webview/native/aw_contents.h
+++ b/android_webview/native/aw_contents.h
@@ -346,10 +346,10 @@ class AwContents : public FindHelper::Listener,
 
   JavaObjectWeakGlobalRef java_ref_;
   AwGLFunctor* functor_;
+  std::unique_ptr<content::WebContents> web_contents_;
   BrowserViewRenderer browser_view_renderer_;  // Must outlive |web_contents_|.
   std::unique_ptr<AwWebContentsDelegate> web_contents_delegate_;
   std::unique_ptr<AwContentsClientBridge> contents_client_bridge_;
-  std::unique_ptr<content::WebContents> web_contents_;
   std::unique_ptr<AwRenderViewHostExt> render_view_host_ext_;
   std::unique_ptr<FindHelper> find_helper_;
   std::unique_ptr<IconHelper> icon_helper_;