Record UMA when googlezip proxies are removed from the proxy config.

chrome/browser/net/pref_proxy_config_tracker_impl.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_NET_PREF_PROXY_CONFIG_TRACKER_IMPL_H_
 #define CHROME_BROWSER_NET_PREF_PROXY_CONFIG_TRACKER_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 63 matching lines @@
   bool registered_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeProxyConfigService);
 };
 
 // A class that tracks proxy preferences. It translates the configuration
 // to net::ProxyConfig and pushes the result over to the IO thread for
 // ChromeProxyConfigService::UpdateProxyConfig to use.
 class PrefProxyConfigTrackerImpl : public PrefProxyConfigTracker {
  public:
+  // Enum values that can be reported for the
+  // Net.PrefProxyConfig.GooglezipProxyRemovalResult histogram. These values
+  // must be kept in sync with their counterparts in histograms.xml. Visible
+  // here for testing purposes.
+  enum GooglezipProxyRemovalResult {
+    GOOGLEZIP_PROXY_REMOVAL_RESULT_NOT_FOUND = 0,
+    GOOGLEZIP_PROXY_REMOVAL_RESULT_FOUND_AND_REMOVED,
+    GOOGLEZIP_PROXY_REMOVAL_RESULT_MAX
+  };
+
   explicit PrefProxyConfigTrackerImpl(PrefService* pref_service);
   ~PrefProxyConfigTrackerImpl() override;
 
   // PrefProxyConfigTracker implementation:
   scoped_ptr<net::ProxyConfigService> CreateTrackingProxyConfigService(
       scoped_ptr<net::ProxyConfigService> base_service) override;
 
   // Notifies the tracker that the pref service passed upon construction is
   // about to go away. This must be called from the UI thread.
   void DetachFromPrefService() override;
@@ skipping 62 matching lines @@
 
   PrefService* pref_service_;
   ChromeProxyConfigService* chrome_proxy_config_service_;  // Weak ptr.
   bool update_pending_;  // True if config has not been pushed to network stack.
   PrefChangeRegistrar proxy_prefs_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefProxyConfigTrackerImpl);
 };
 
 #endif  // CHROME_BROWSER_NET_PREF_PROXY_CONFIG_TRACKER_IMPL_H_