Don't clear the activeTab permission for same-origin navigations when the

chrome/browser/extensions/active_tab_permission_granter.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/extensions/active_tab_permission_granter.h"
 
 #include "chrome/browser/extensions/active_script_controller.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension_messages.h"
+#include "extensions/common/feature_switch.h"
 #include "extensions/common/permissions/permission_set.h"
 #include "extensions/common/permissions/permissions_data.h"
 #include "extensions/common/user_script.h"
 #include "url/gurl.h"
 
 using content::RenderProcessHost;
 using content::WebContentsObserver;
 
 namespace extensions {
 
@@ skipping 59 matching lines @@
     }
   }
 }
 
 void ActiveTabPermissionGranter::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   if (details.is_in_page)
     return;
   DCHECK(details.is_main_frame);  // important: sub-frames don't get granted!
-  ClearActiveExtensionsAndNotify();
+
+  // See http://crbug.com/404243 for why we do this. Only do this when the
+  // script-require-action flag is on, since it's not clear it's generally a
+  // good idea. However, the scripts-require-action feature is all-but unusable
+  // without this behaviour.
+  if (details.previous_url.GetOrigin() != details.entry->GetURL().GetOrigin() ||

[Devlin, 2014/08/15 21:24:00]

I seem to recall that NavigationEntries are one of those pesky things that's
sometimes NULL.  Do we need to check that here?

[not at google - send to devlin, 2014/08/15 21:38:29]

Ah yes, good point. Fixed.

+      !FeatureSwitch::scripts_require_action()->IsEnabled()) {
+    ClearActiveExtensionsAndNotify();
+  }
 }
 
 void ActiveTabPermissionGranter::WebContentsDestroyed() {
   ClearActiveExtensionsAndNotify();
 }
 
 void ActiveTabPermissionGranter::OnExtensionUnloaded(
     content::BrowserContext* browser_context,
     const Extension* extension,
     UnloadedExtensionInfo::Reason reason) {
@@ skipping 12 matching lines @@
        it != granted_extensions_.end(); ++it) {
     it->get()->permissions_data()->ClearTabSpecificPermissions(tab_id_);
     extension_ids.push_back((*it)->id());
   }
 
   Send(new ExtensionMsg_ClearTabSpecificPermissions(tab_id_, extension_ids));
   granted_extensions_.Clear();
 }
 
 }  // namespace extensions