[Extensions] Add renderer-side logic to short circuit activity logging

chrome/browser/extensions/activity_log/activity_log.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_H_
 #define CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 100 matching lines @@
   // Clean up URLs from the activity log database.
   // If restrict_urls is empty then all URLs in the activity log database are
   // removed, otherwise only those in restrict_urls are removed.
   void RemoveURLs(const std::vector<GURL>& restrict_urls);
   void RemoveURLs(const std::set<GURL>& restrict_urls);
   void RemoveURL(const GURL& url);
 
   // Deletes the database associated with the policy that's currently in use.
   void DeleteDatabase();
 
+  bool is_active() const { return is_active_; }

[asargent_no_longer_on_chrome, 2016/06/23 13:35:56]

nit: this could use a comment with an explanation of what "active" means

[Devlin, 2016/06/23 16:59:02]

There is a comment on the |is_active_|, and I think for accessors we don't add
additional documentation (because one or the other will likely forget to be
updated).  But I added some more detail to the |is_active_| description, since
it was rather sparse.

+
   // If we're in a browser test, we need to pretend that the watchdog app is
   // active.
   void SetWatchdogAppActiveForTesting(bool active);
 
  private:
   friend class ActivityLogTest;
   friend class BrowserContextKeyedAPIFactory<ActivityLog>;
 
   explicit ActivityLog(content::BrowserContext* context);
   ~ActivityLog() override;
@@ skipping 85 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(ActivityLogEnabledTest, WatchdogSwitch);
   DISALLOW_COPY_AND_ASSIGN(ActivityLog);
 };
 
 template <>
 void BrowserContextKeyedAPIFactory<ActivityLog>::DeclareFactoryDependencies();
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_H_