webRequest: reliably determine tabId

extensions/browser/extension_api_frame_id_map.cc

 // Copyright 2015 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 "extensions/browser/extension_api_frame_id_map.h"
 
 #include <tuple>
 
 #include "base/metrics/histogram_macros.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 114 matching lines @@
   if (navigation_handle->IsInMainFrame())
     return -1;
 
   if (navigation_handle->IsParentMainFrame())
     return 0;
 
   return navigation_handle->GetParentFrameTreeNodeId();
 }
 
 // static
+void ExtensionApiFrameIdMap::GetTabAndWindowId(content::RenderFrameHost* rfh,
+                                               int* tab_id_out,
+                                               int* window_id_out) {
+  ExtensionApiFrameIdMapHelper* helper =

[Devlin, 2016/05/23 16:23:18]

(if we keep this, dcheck ui thread)

Why do we do this instead of (possibly caching and) returning the FrameData?  If
there isn't a cached frame data, there should be, since we'll probably need it
later.

[robwu, 2016/05/23 17:55:55]

I didn't realize that the tab ID was immediately set as a part of the lookup
since the documentation in the header file only mentioned tabId.
I've fixed the inaccurate comments and used FrameData instead.

+      ExtensionApiFrameIdMap::Get()->helper_.get();
+  if (helper)
+    helper->GetTabAndWindowId(rfh, tab_id_out, window_id_out);
+}
+
+// static
 content::RenderFrameHost* ExtensionApiFrameIdMap::GetRenderFrameHostById(
     content::WebContents* web_contents,
     int frame_id) {
   // Although it is technically possible to map |frame_id| to a RenderFrameHost
   // without WebContents, we choose to not do that because in the extension API
   // frameIds are only guaranteed to be meaningful in combination with a tabId.
   if (!web_contents)
     return nullptr;
 
   if (frame_id == kInvalidFrameId)
@@ skipping 200 matching lines @@
 }
 
 void ExtensionApiFrameIdMap::RemoveFrameData(const RenderFrameIdKey& key) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   base::AutoLock lock(frame_data_map_lock_);
   frame_data_map_.erase(key);
 }
 
 }  // namespace extensions