[android] Resize the android_webview if it's 0x0 initially.

android_webview/browser/renderer_host/view_renderer_host.h

Index: android_webview/browser/renderer_host/view_renderer_host.h
diff --git a/android_webview/browser/renderer_host/view_renderer_host.h b/android_webview/browser/renderer_host/view_renderer_host.h
index 4cb2501e9ad3eff7b3b8366f5c714ff71bf90d1d..42b96079e973626bd26bff1f45c85f1aa7c5100f 100644
--- a/android_webview/browser/renderer_host/view_renderer_host.h
+++ b/android_webview/browser/renderer_host/view_renderer_host.h
@@ -18,6 +18,9 @@ class ViewRendererHost : public content::WebContentsObserver,
   class Client {
    public:
     virtual void OnPictureUpdated(int process_id, int render_view_id) = 0;
+    virtual void OnPageScaleFactorChanged(int process_id,
+                                          int render_view_id,
+                                          float page_scale_factor) = 0;
 
    protected:
     virtual ~Client() {}
@@ -43,6 +46,7 @@ class ViewRendererHost : public content::WebContentsObserver,
 
   void OnPictureUpdated();
   void OnDidActivateAcceleratedCompositing(int input_handler_id);
+  void OnPageScaleFactorChanged(float page_scale_factor);
 
   bool IsRenderViewReady() const;