Implement Mac Pop-up Dictionary for OOPIF.

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index b3ed29f84d08a5098252a45351329f3da0a7d998..d6e2a76e21a8b5290442b44b4ea096e3a3eee948 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -380,6 +380,10 @@ class CONTENT_EXPORT RenderWidget
     focused_pepper_plugin_ = plugin;
   }
 
+  PepperPluginInstanceImpl* focused_pepper_plugin() const {

[Charlie Reis, 2016/08/31 22:50:03]

lfg@: Can you review this part?  I know you had some thoughts on this recently.

[lfg, 2016/09/01 15:42:27]

I really don't like this. We shouldn't be exposing focused_pepper_plugin()
through RenderWidget. I was ok with adding this to RenderWidget because we had
to fix the blocking issue with IME, but I think we should now try to find a
better solution.

Here's what I propose: 1) Add a RenderWidgetDelegate abstraction that has the
needed IME-related functions. 2) Add an IME class the implements
RenderWidgetDelegate. This IME class can keep track of all the frames in the
local root, and we should rely on the RenderFrame as the only source for the
focused_pepper_plugin (we already saw that having this in RenderWidget is
fragile with a use-after-free last week).

[EhsanK, 2016/09/01 21:58:37]

For now I have removed this line of code and pass RenderFrameImpl (local root)
to TextInputClientObserver).

I think having a middle interface like the RenderWidgetDelegate is very useful.
I am not sure if RenderFrameImpl is a good candidate for implementing the
interface, or we should have a separate implementation owned by (maybe)
RenderFrame.

[lfg, 2016/09/02 16:39:00]

Can you file a bug and add a TODO to fix the focused_pepper_plugin issue in
RenderWidget?

+    return focused_pepper_plugin_;
+  }
+
   // When emulated, this returns original device scale factor.
   float GetOriginalDeviceScaleFactor() const;