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..b961c7c1d753077da43fc40668c5fbd50807a26f 100644
--- a/third_party/WebKit/public/web/mac/WebSubstringUtil.h
+++ b/third_party/WebKit/public/web/mac/WebSubstringUtil.h
@@ -43,15 +43,22 @@ class NSAttributedString;
 namespace blink {
 
 class WebView;
+class WebWidget;
 struct WebPoint;
 
 class WebSubstringUtil {
 public:
+    // TODO(ekaramad): This method should only receive a WebWidget. But for the
+    // main frame, WebWidget is in fact a WebViewImpl. Since WebViewImpl has
+    // protected inheritance from WebWidget, we cannot downcast further to get
+    // it from its WebWidget reference. This extra parameter will be removed
+    // once WebViewImpl 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);