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..25a00c8b3a3d3bac743355cebc596222512af587 100644
--- a/extensions/browser/extension_api_frame_id_map.cc
+++ b/extensions/browser/extension_api_frame_id_map.cc
@@ -306,6 +306,14 @@ bool ExtensionApiFrameIdMap::GetCachedFrameDataOnIO(int render_process_id,
   return found;
 }
 
+ExtensionApiFrameIdMap::FrameData ExtensionApiFrameIdMap::GetFrameData(
+    content::RenderFrameHost* rfh) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  const RenderFrameIdKey key(rfh->GetProcess()->GetID(), rfh->GetRoutingID());
+  return LookupFrameDataOnUI(key, true /* for lookup */);

[Devlin, 2016/05/23 20:28:48]

In retrospect, this was probably a poorly named boolean.  The idea here is that
we're recording how often we find the value for a frame after a cache miss
(indicating the value of performing the thread hop).  Since there was no initial
cache miss here, I'd prefer not to record for this case.  It would probably be
good to also rename the boolean to something like "for_lookup_after_cache_miss"
to make this more clear.

[robwu, 2016/05/23 20:54:15]

Done. for_lookup_after_cache_miss was a bit too long for my like, so I went with
is_from_io instead.

[Devlin, 2016/05/23 20:56:12]

sgtm

+}
+
 void ExtensionApiFrameIdMap::CacheFrameData(content::RenderFrameHost* rfh) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);