Fix copying from interstitial pages on OSX.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 05f980664b463b1a958203d03c01e31495ab56ac..7be448fb503a64055f047f7fe96af8b6c996809d 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -645,6 +645,11 @@ RenderFrameHostImpl* WebContentsImpl::GetMainFrame() {
 }
 
 RenderFrameHost* WebContentsImpl::GetFocusedFrame() {
+  if (ShowingInterstitialPage()) {
+    InterstitialPageImpl* interstitial_page =
+        static_cast<InterstitialPageImpl*>(GetInterstitialPage());
+    return interstitial_page->GetMainFrame();

[Charlie Reis, 2015/04/27 23:39:26]

This is mildly scary to me.  We're returning a frame that is not in the frame
tree of the WebContents, which could have undefined behavior in any call sites
that make that assumption.

Maybe it's reasonable since this is specific to focus and kind of makes sense
conceptually, but it feels really risky to me.

+  }
   if (!frame_tree_.GetFocusedFrame())
     return NULL;
   return frame_tree_.GetFocusedFrame()->current_frame_host();