webRequest: reliably determine tabId

extensions/browser/extension_api_frame_id_map.cc

Index: extensions/browser/extension_api_frame_id_map.cc
diff --git a/extensions/browser/extension_api_frame_id_map.cc b/extensions/browser/extension_api_frame_id_map.cc
index d8566f97598cca9bd3f513da1ec5e5baf7dc40c1..39362e9871b7c0eba1154959ff78fc0cad5c324e 100644
--- a/extensions/browser/extension_api_frame_id_map.cc
+++ b/extensions/browser/extension_api_frame_id_map.cc
@@ -132,6 +132,16 @@ int ExtensionApiFrameIdMap::GetParentFrameId(
 }
 
 // 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) {