Fix View Frame Source for iframe of a file:// URL shows main frame's filename

chrome/browser/ui/browser_commands.cc

Index: chrome/browser/ui/browser_commands.cc
diff --git a/chrome/browser/ui/browser_commands.cc b/chrome/browser/ui/browser_commands.cc
index 89f35b6ecb9be583578c026861e89727d203965e..4c8f6cb4bf57bede8b1f79058dc960a44305beb9 100644
--- a/chrome/browser/ui/browser_commands.cc
+++ b/chrome/browser/ui/browser_commands.cc
@@ -1204,6 +1204,7 @@ void ViewSource(Browser* browser,
   GURL view_source_url =
       GURL(content::kViewSourceScheme + std::string(":") + url.spec());
   last_committed_entry->SetVirtualURL(view_source_url);
+  last_committed_entry->SetURL(GURL());

[Charlie Reis, 2016/11/17 23:04:24]

Hmm, I'm not sure this is safe.  There are other places that we check the
NavigationEntry's URL to make decisions, and it looks like this would leave it
empty.  Does it get set again later, like at commit?  That still might do the
wrong thing while it's a pending entry (e.g., if it's a slow URL, what would we
show in the address bar before commit?).

[afakhry, 2016/11/19 01:49:29]

Yes, it gets set again later as a result of receiving a message:

|#2 0x2b8f44714a17 content::NavigationEntryImpl::SetURL()
|#3 0x2b8f447061e5
content::NavigationControllerImpl::RendererDidNavigateToNewPage()
|#4 0x2b8f44704fec content::NavigationControllerImpl::RendererDidNavigate()
|#5 0x2b8f44732d15 content::NavigatorImpl::DidNavigate()
|#6 0x2b8f4473d567 content::RenderFrameHostImpl::OnDidCommitProvisionalLoad()
|#7 0x2b8f4473a798 content::RenderFrameHostImpl::OnMessageReceived()
|#8 0x2b8f44c5fd12 content::RenderProcessHostImpl::OnMessageReceived()
|#9 0x2b8f42fd5178 IPC::ChannelProxy::Context::OnDispatchMessage()

I've just tried it. If it's a slow page in the iframe, viewing frame source
still shows the right title with this fix.

Isn't this the last committed entry of the newly-cloned webcontents that will be
used to show the source? Do we really care about it's URL? Isn't it only used to
show the source?
If using an empty URL could cause problems, how about using the virtual url?

I'm sorry I don't have much knowledge of this area of the code.

 
   // Do not restore scroller position.
   last_committed_entry->SetPageState(page_state.RemoveScrollOffset());