Make browser_handles_top_level_requests synchronous.

chrome/browser/external_tab/external_tab_container_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/external_tab/external_tab_container_win.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 390 matching lines @@
       }
       break;
     default:
       NOTREACHED();
       break;
   }
 
   return NULL;
 }
 
+bool ExternalTabContainer::ShouldIgnoreNavigation(
+    WebContents* source,
+    const GURL& url,
+    const content::Referrer& referrer,
+    WindowOpenDisposition disposition,
+    bool is_content_intiated,

[Charlie Reis, 2012/04/05 17:06:53]

nit: initiated

[mkosiba (inactive), 2012/04/10 17:58:37]

Done.

+    content::PageTransition transition_type) {
+  // This will make every navigation browser-initiated.
+  // TODO: Investigate modifying ExternalTabContainer to work without canceling
+  // and re-issuing every navigation.

[Charlie Reis, 2012/04/05 17:06:53]

This TODO seems critical.  We can't treat every link click as a
browser-initiated navigation.  That would introduce process swaps for every type
of cross-site navigation, which would break script connections between tabs in
real cases.  We're currently very careful about when we use process swaps for
this reason-- see the Caveats section of this page for details:
http://dev.chromium.org/developers/design-documents/process-models

(Note: as mentioned below, I'm not sure when this class is used, so I'm not sure
how often this problem will arise.)

[mkosiba (inactive), 2012/04/10 17:58:37]

This is exactly how browser_handles_top_level_requests works now - every link
click is forced to be a browser-initiated navigation (take a look at the code in
decidePolicyForNavigation).

The reason I'm not making more changes here is because I'm assuming
ExternalTabContainer clients are depending on this behavior (pessimistic
assumption - I don't know this for a fact)

+
+  if (is_content_intiated)
+    source->GetController().LoadURL(url, referrer, transition_type,
+                                    std::string());
+  return true;
+}
+
 void ExternalTabContainer::NavigationStateChanged(const WebContents* source,
                                                   unsigned changed_flags) {
   if (automation_) {
     NavigationInfo nav_info;
     if (InitNavigationInfo(&nav_info, content::NAVIGATION_TYPE_NAV_IGNORE, 0))
       automation_->Send(new AutomationMsg_NavigationStateChanged(
           tab_handle_, changed_flags, nav_info));
   }
 }
 
@@ skipping 788 matching lines @@
   if (params.disposition == CURRENT_TAB) {
     DCHECK(route_all_top_level_navigations_);
     forward_params.disposition = NEW_FOREGROUND_TAB;
   }
   WebContents* new_contents =
       ExternalTabContainer::OpenURLFromTab(source, forward_params);
   // support only one navigation for a dummy tab before it is killed.
   ::DestroyWindow(GetNativeView());
   return new_contents;
 }