Emit error events if the loading of an object element failed

components/plugins/renderer/webview_plugin.h

Index: components/plugins/renderer/webview_plugin.h
diff --git a/components/plugins/renderer/webview_plugin.h b/components/plugins/renderer/webview_plugin.h
index 7f4ad1045a850bad918d6c85c898a0247a61a71a..161ebf19874aafc1cdb98acee645198647a49e4a 100644
--- a/components/plugins/renderer/webview_plugin.h
+++ b/components/plugins/renderer/webview_plugin.h
@@ -105,6 +105,9 @@ class WebViewPlugin : public blink::WebPlugin,
   void didReceiveData(const char* data, int data_length) override;
   void didFinishLoading() override;
   void didFailLoading(const blink::WebURLError& error) override;
+  bool isPlaceholder() override;
+  void markAsErrorPlaceholder();

[Bernhard Bauer, 2017/03/28 10:55:59]

These two methods are not overrides of WebPlugin, so they should not be grouped
with isPlaceholder().

Coming to think of it, whether or not this is an error placeholder is really
defined by the client of this class, so instead of using a flag in here we could
make this a delegate method. PluginPlaceholderBase would implement the delegate
method to return false, and LoadablePluginPlaceholder would return
!allow_loading_.

[George Joseph, 2017/03/30 08:41:43]

Done.

+  void unmarkAsErrorPlaceholder();
 
  private:
   friend class base::DeleteHelper<WebViewPlugin>;
@@ -138,6 +141,7 @@ class WebViewPlugin : public blink::WebPlugin,
   bool focused_;
   bool is_painting_;
   bool is_resizing_;
+  bool placeholder = false;

[Bernhard Bauer, 2017/03/28 10:55:59]

Member variables in Chromium style end with an underscore. (Although we can
remove this member, see above.)

[George Joseph, 2017/03/30 08:41:43]

Done.

 
   // A helper that handles interaction from WebViewPlugin's internal WebView.
   class WebViewHelper : public blink::WebViewClient,