Switch CoreTabHelper to use WebContentsUserData.

chrome/browser/prerender/prerender_manager.cc

Index: chrome/browser/prerender/prerender_manager.cc
diff --git a/chrome/browser/prerender/prerender_manager.cc b/chrome/browser/prerender/prerender_manager.cc
index 82cf8b1fc03b1c7e892c9c4f4f70820cb2a1c6b7..4a0be94df3542849dee467cc8baeee7cc8fb7d33 100644
--- a/chrome/browser/prerender/prerender_manager.cc
+++ b/chrome/browser/prerender/prerender_manager.cc
@@ -396,14 +396,16 @@ bool PrerenderManager::MaybeUsePrerenderedPage(WebContents* web_contents,
   TabContents* old_tab_contents = TabContents::FromWebContents(web_contents);
   DCHECK(new_tab_contents);
   DCHECK(old_tab_contents);
+  WebContents* new_web_contents = new_tab_contents->web_contents();
+  WebContents* old_web_contents = web_contents;
 

[gavinp, 2012/09/14 23:42:21]

Why create all these aliases, including a rename of a parameter, just to add one
call to CoreTabHelper::FromWebContents? I think the call would be shorter if you
just narrowed your changes to the one line?

[Avi (use Gerrit), 2012/09/17 16:05:12]

I'm in the process of killing TabContents, so this is a bit more of a
forward-looking patch. I'm introducing WebContents versions of the data,
switching over to them where I can and only using the TabContents versions where
I must. Once I've switched enough things over to WebContents, the TabContents
versions go away.

[gavinp, 2012/09/19 04:03:51]

I'd rather review that change when it happens, I think. Even if the intermediate
state is temporary, I'd rather not see all these extra nearly synonymic
variables, even briefly.

Would it make sense to minimize to the one line for this commit, and then do the
bigger rename, removing the tab contents too, when the new webcontents interface
is available?

-  MarkWebContentsAsPrerendered(new_tab_contents->web_contents());
+  MarkWebContentsAsPrerendered(new_web_contents);
 
   // Merge the browsing history.
-  new_tab_contents->web_contents()->GetController().CopyStateFromAndPrune(
-      &old_tab_contents->web_contents()->GetController());
-  old_tab_contents->core_tab_helper()->delegate()->
-      SwapTabContents(old_tab_contents, new_tab_contents);
+  new_web_contents->GetController().CopyStateFromAndPrune(
+      &old_web_contents->GetController());
+  CoreTabHelper::FromWebContents(old_web_contents)->delegate()->

[gavinp, 2012/09/14 23:42:21]

i.e. change only this line.

+      SwapTabContents(old_web_contents, new_web_contents);
   prerender_contents->CommitHistory(new_tab_contents);
 
   GURL icon_url = prerender_contents->icon_url();
@@ -423,12 +425,11 @@ bool PrerenderManager::MaybeUsePrerenderedPage(WebContents* web_contents,
   DCHECK(prerender_tab_helper != NULL);
   prerender_tab_helper->PrerenderSwappedIn();
 
-  if (old_tab_contents->web_contents()->NeedToFireBeforeUnload()) {
+  if (old_web_contents->NeedToFireBeforeUnload()) {
     // Schedule the delete to occur after the tab has run its unload handlers.
     on_close_tab_contents_deleters_.push_back(
         new OnCloseTabContentsDeleter(this, old_tab_contents));
-    old_tab_contents->web_contents()->GetRenderViewHost()->
-        FirePageBeforeUnload(false);
+    old_web_contents->GetRenderViewHost()->FirePageBeforeUnload(false);
   } else {
     // No unload handler to run, so delete asap.
     ScheduleDeleteOldTabContents(old_tab_contents, NULL);