Implement Mac Pop-up Dictionary for OOPIF.

third_party/WebKit/Source/web/mac/WebSubstringUtil.mm

Index: third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
diff --git a/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm b/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
index c32db74669ef2c763a1399629e7f4166298cc9fb..a8fbc592b78a1835244ab48cde3bd5ebede1b584 100644
--- a/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
+++ b/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
@@ -53,6 +53,9 @@
 #include "public/web/WebHitTestResult.h"
 #include "public/web/WebRange.h"
 #include "public/web/WebView.h"
+#include "public/web/WebWidget.h"
+#include "web/WebFrameWidgetBase.h"
+#include "web/WebFrameWidgetImpl.h"
 #include "web/WebLocalFrameImpl.h"
 #include "web/WebViewImpl.h"
 
@@ -136,9 +139,17 @@ WebPoint getBaselinePoint(FrameView* frameView, const EphemeralRange& range, NSA
 
 namespace blink {
 
-NSAttributedString* WebSubstringUtil::attributedWordAtPoint(WebView* view, WebPoint point, WebPoint& baselinePoint)
+NSAttributedString* WebSubstringUtil::attributedWordAtPoint(WebView* view, WebWidget* widget, WebPoint point, WebPoint& baselinePoint)
 {
-    HitTestResult result = static_cast<WebViewImpl*>(view)->coreHitTestResultAt(point);
+    WebViewImpl* viewImpl = static_cast<WebViewImpl*>(view);
+
+    // Either this call is for a main frame's WebView or a local roots WebFrameWidgetImpl.
+    if (!viewImpl->mainFrameImpl() && !widget)
+        return nil;
+
+    // Either we are in the main frame, where |widget| is a WebViewImpl equal to |view|, or, |widget| is a WebFrameWidget.
+    HitTestResult result = widget->isWebView() ? viewImpl->coreHitTestResultAt(point) : static_cast<WebFrameWidgetImpl*>(widget)->coreHitTestResultAt(point);

[kenrb, 2016/09/12 17:28:13]

It looks like you dereference widget without first guaranteeing that it isn't
null (you checked that mainFrameImpl() OR widget is null, which isn't
sufficient).

Please check this with lfg@, who has been working on the WebView/WebWidget split
and might have advice on how to structure this.

[EhsanK, 2016/09/13 18:52:15]

I believe neither |view| nor (specifically) |widget| are nullptr when we reach
this point. This call comes from RenderWidget which already owns a WebWidget.
The reason we have a view and widget here is that I cannot cast WebWidget to
WebViewImpl. However, with Lucas's patch coming up I think I will declare the
method coreHitTestResultAt  in WebFrameWidgetBase and implement in both
WebFrameWidgetImpl and WebViewFrameWidget (which would simply call the m_webView
one). With that this ugliness will be removed.

+
     if (!result.innerNode())
         return nil;
     LocalFrame* frame = result.innerNode()->document().frame();