Don't serialize extension user script injection results unless the extension

chrome/renderer/extensions/chrome_v8_context_set.cc

Index: chrome/renderer/extensions/chrome_v8_context_set.cc
diff --git a/chrome/renderer/extensions/chrome_v8_context_set.cc b/chrome/renderer/extensions/chrome_v8_context_set.cc
index 49c93978d666fb33272ac1a0d6662fd3f75bf5f0..228a3c6459dce01ad9a6228cd69520d0e48c3963 100644
--- a/chrome/renderer/extensions/chrome_v8_context_set.cc
+++ b/chrome/renderer/extensions/chrome_v8_context_set.cc
@@ -76,7 +76,16 @@ ChromeV8Context* ChromeV8ContextSet::GetByV8Context(
     if ((*iter)->v8_context() == v8_context)
       return *iter;
   }
+  return NULL;
+}
 
+ChromeV8Context* ChromeV8ContextSet::GetByWebFrame(
+    WebKit::WebFrame* web_frame) const {
+  for (ContextSet::const_iterator iter = contexts_.begin();
+       iter != contexts_.end(); ++iter) {
+    if ((*iter)->web_frame() == web_frame)
+      return *iter;
+  }
   return NULL;
 }