Fix devtools unable to start a shared workers.

chrome/browser/search/iframe_source.cc

Index: chrome/browser/search/iframe_source.cc
diff --git a/chrome/browser/search/iframe_source.cc b/chrome/browser/search/iframe_source.cc
index 511cd48a0d7082294bb4a228f15f550d50607977..e9dd3b646de7f515f0182e6581d29348197fa362 100644
--- a/chrome/browser/search/iframe_source.cc
+++ b/chrome/browser/search/iframe_source.cc
@@ -52,7 +52,11 @@ bool IframeSource::ShouldDenyXFrameOptions() const {
 bool IframeSource::GetOrigin(
     const content::ResourceRequestInfo::WebContentsGetter& wc_getter,
     std::string* origin) const {
+  if (wc_getter.is_null())
+    return false;
   content::WebContents* contents = wc_getter.Run();
+  if (!contents)
+    return false;
   const content::NavigationEntry* entry =
       contents->GetController().GetVisibleEntry();
   if (entry == NULL)