Fix broken mixed script Rappor metric and add browser test

chrome/renderer/content_settings_observer.cc

Index: chrome/renderer/content_settings_observer.cc
diff --git a/chrome/renderer/content_settings_observer.cc b/chrome/renderer/content_settings_observer.cc
index 8bf046741d65ffa0b06a4183bd22d5d53de35c2c..010a9e1e8eeee8833e2be9ac241f2f9fe2989ea5 100644
--- a/chrome/renderer/content_settings_observer.cc
+++ b/chrome/renderer/content_settings_observer.cc
@@ -483,7 +483,9 @@ bool ContentSettingsObserver::allowRunningInsecureContent(
     SendInsecureContentSignal(INSECURE_CONTENT_RUN_SWF);
 
   if (!allow_running_insecure_content_ && !allowed_per_settings) {
-    DidBlockContentType(CONTENT_SETTINGS_TYPE_MIXEDSCRIPT, origin.host());
+    // The browser process expects the |details| argument to contain a
+    // valid GURL from which the mixed script was run.
+    DidBlockContentType(CONTENT_SETTINGS_TYPE_MIXEDSCRIPT, origin.toString());
     return false;
   }