Implement Mac Pop-up Dictionary for OOPIF.

third_party/WebKit/public/web/mac/WebSubstringUtil.h

Index: third_party/WebKit/public/web/mac/WebSubstringUtil.h
diff --git a/third_party/WebKit/public/web/mac/WebSubstringUtil.h b/third_party/WebKit/public/web/mac/WebSubstringUtil.h
index 29c9cdd24f2f73d09f49848938116d63811b772a..15cc68fde482955b1b481aa67f4f7c0d6a48c4f2 100644
--- a/third_party/WebKit/public/web/mac/WebSubstringUtil.h
+++ b/third_party/WebKit/public/web/mac/WebSubstringUtil.h
@@ -43,15 +43,20 @@ class NSAttributedString;
 namespace blink {
 
 class WebView;
+class WebWidget;
 struct WebPoint;
 
 class WebSubstringUtil {
 public:
+    // TODO(ekaramad): This method should only receive a WebWidget. But due to

[erikchen, 2016/09/01 00:04:29]

Is there a typo in this comment? I think one of the instances of WebWidget
should be changed to WebView?

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

It is correct but vague perhaps. I reworded this. Thanks!

Ideally, we want only WebWidget here. The reason is that this operation should
be handled by RenderWidget (the IPC is sent to RenderWidget). But inside
RenderWidget we only have a WebWidget reference.  Although WebViewImpl is a
WebWidget, but the inheritance is protected so here I cannot rely on only
WebWidget reference to handle the WebViewImpl case (for the main frame).

+    // protectedness of WebView's inheritance from WebWidget we cannot downcast
+    // from WebWidget. Change this when WebView is no longer a WebWidget.
     // Returns an autoreleased NSAttributedString that is the word under
     // the given point, or nil on error.
     // Upon return, |baselinePoint| is set to the left baseline point in
     // AppKit coordinates.
     BLINK_EXPORT static NSAttributedString* attributedWordAtPoint(WebView*,
+        WebWidget*,
         WebPoint,
         WebPoint& baselinePoint);