Fix user agent override restoration pipeline
    
There were some disconnects in the pipeline that prevented the user agent override
string from being saved and restored from the temporary tab structions in sessions/,
but couldn't be tested on Android because the pathways weren't being exercised in
the same way.  This CL finishes hooking it up for ChromeOS (and presumably the other
platforms).
    
BUG=140600


Review URL: https://chromiumcodereview.appspot.com/10827168

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152207 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index cee3043..d4c3dafb 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -808,6 +808,9 @@
   NavigationEntry* entry = controller_.GetActiveEntry();
   if (is_loading_ && entry != NULL && entry->GetIsOverridingUserAgent())
     controller_.ReloadIgnoringCache(true);
+
+  FOR_EACH_OBSERVER(WebContentsObserver, observers_,
+                    UserAgentOverrideSet(override));
 }
 
 const std::string& WebContentsImpl::GetUserAgentOverride() const {