Emit error events if the loading of an object element failed

third_party/WebKit/public/web/WebPlugin.h

Index: third_party/WebKit/public/web/WebPlugin.h
diff --git a/third_party/WebKit/public/web/WebPlugin.h b/third_party/WebKit/public/web/WebPlugin.h
index 6e6403a7a6a5e5ce5129610d46044c0bbe83a7b6..5a490bd64d2aeed58af11d75780d6061ce0e7914 100644
--- a/third_party/WebKit/public/web/WebPlugin.h
+++ b/third_party/WebKit/public/web/WebPlugin.h
@@ -238,6 +238,12 @@ class WebPlugin {
   virtual void rotateView(RotationType type) {}
 
   virtual bool isPlaceholder() { return true; }
+  // Check whether a plugin load lead to the instantiation of a
+  // PluginPlaceholderBase derived plugin, which is not allowed

[Bernhard Bauer, 2017/03/31 09:25:20]

This is a layering violation, as Blink shouldn't know about Chrome code.

[George Joseph, 2017/04/03 00:22:34]

Done.

+  // to load later on. isPlaceholder() is used by the pepper

[Bernhard Bauer, 2017/03/31 09:25:20]

This sentence should be a comment on isPlaceholder, but it also violates the
layering. It also doesn't actually convey much more information than is already
in the name.

AFAIU, the big difference is that isPlaceholder() returns whether the plugin
can't be interacted with _right now_ but might load later, whereas
isErrorPlaceholder() returns whether the plugin will _never_ load (and therefore
we should emit the error event).

+  // webplugin implementation to check if a WebHelperPlugin
+  // did create a PlaceHolder Plugin.

[Bernhard Bauer, 2017/03/31 09:25:20]

Nit: capitalized weirdly (placeholder should be a single lowercased word, as
should plugin).

[George Joseph, 2017/04/03 00:22:34]

Done.

+  virtual bool isErrorPlaceholder() { return false; };

[Bernhard Bauer, 2017/03/31 09:25:21]

Nit: No semicolon after the closing brace.

[George Joseph, 2017/04/03 00:22:34]

Done.

 
  protected:
   ~WebPlugin() {}