Fix broken mixed script Rappor metric and add browser test

chrome/browser/content_settings/tab_specific_content_settings.h

Index: chrome/browser/content_settings/tab_specific_content_settings.h
diff --git a/chrome/browser/content_settings/tab_specific_content_settings.h b/chrome/browser/content_settings/tab_specific_content_settings.h
index dc20cd102122327bfc9bba8173c947eaabe916de..e8bb842a9bf64327aaf44bd044135ddd378dc322 100644
--- a/chrome/browser/content_settings/tab_specific_content_settings.h
+++ b/chrome/browser/content_settings/tab_specific_content_settings.h
@@ -37,6 +37,10 @@ namespace net {
 class CookieOptions;
 }
 
+namespace rappor {
+class RapporService;
+}
+
 // This class manages state about permissions, content settings, cookies and
 // site data for a specific WebContents. It tracks which content was accessed
 // and which content was blocked. Based on this it provides information about
@@ -366,6 +370,9 @@ class TabSpecificContentSettings
   // Block all content. Used for testing content setting bubbles.
   void BlockAllContentForTesting();
 
+  // Set the Rappor service used for testing.
+  void SetRapporServiceForTesting(rappor::RapporService* rappor_service);
+
  private:
   friend class content::WebContentsUserData<TabSpecificContentSettings>;
 
@@ -470,6 +477,9 @@ class TabSpecificContentSettings
   // Observer to watch for content settings changed.
   ScopedObserver<HostContentSettingsMap, content_settings::Observer> observer_;
 
+  // The service used to record Rappor metrics. Can be set for testing.
+  rappor::RapporService* rappor_service_;
+
   DISALLOW_COPY_AND_ASSIGN(TabSpecificContentSettings);
 };