Properly propagate the current Chrome channel into the Feature system on the

chrome/common/extensions/features/feature.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_COMMON_EXTENSIONS_FEATURES_FEATURE_H_
 #define CHROME_COMMON_EXTENSIONS_FEATURES_FEATURE_H_
 
 #include <set>
 #include <string>
 
@@ skipping 50 matching lines @@
     INVALID_MIN_MANIFEST_VERSION,
     INVALID_MAX_MANIFEST_VERSION,
     NOT_PRESENT,
     UNSUPPORTED_CHANNEL,
   };
 
   Feature();
   Feature(const Feature& other);
   virtual ~Feature();
 
-  // (Re)Sets whether checking against "channel" should be done. This must only
-  // be called on the browser process, since the check involves accessing the
-  // filesystem.
-  // See http://crbug.com/126535.
-  static void SetChannelCheckingEnabled(bool enabled);
-  static void ResetChannelCheckingEnabled();
+  // Returns true if a channel has been set.
+  static bool HasCurrentChannel();
 
-  // (Re)Sets the Channel to for all Features to compare against. This is
-  // usually chrome::VersionInfo::GetChannel(), but for tests allow this to be
-  // overridden.
-  static void SetChannelForTesting(chrome::VersionInfo::Channel channel);
-  static void ResetChannelForTesting();
+  // Gets the current channel as seen by the Feature system.
+  // SetCurrentChannel() must have already been called.
+  static chrome::VersionInfo::Channel GetCurrentChannel();
 
-  // Returns the current channel as seen by the Feature system (i.e. the
-  // ChannelForTesting if one is set, otherwise the actual channel).
-  static chrome::VersionInfo::Channel GetCurrentChannel();
+  // Sets the current channel as seen by the Feature system. In the browser
+  // process this should be chrome::VersionInfo::GetChannel(), and in the
+  // renderer this will need to come from an IPC.
+  static void SetCurrentChannel(chrome::VersionInfo::Channel channel);
+
+  // Clears the current channel as seen by the Feature system.
+  static void ClearCurrentChannel();
+
+  // Scoped channel setter. Use for tests.
+  class ScopedCurrentChannel {
+   public:
+    explicit ScopedCurrentChannel(chrome::VersionInfo::Channel channel)
+        : has_original_channel_(false),
+          original_channel_(chrome::VersionInfo::CHANNEL_UNKNOWN) {
+      if (HasCurrentChannel()) {
+        has_original_channel_ = true;
+        original_channel_ = GetCurrentChannel();
+      }
+      SetCurrentChannel(channel);
+    }
+
+    ~ScopedCurrentChannel() {
+      if (has_original_channel_)
+        SetCurrentChannel(original_channel_);

[Matt Perry, 2012/08/08 19:17:26]

else: ClearCurrentChannel?

[not at google - send to devlin, 2012/08/09 00:14:37]

Oops. Thanks.

+    }
+
+   private:
+    bool has_original_channel_;
+    chrome::VersionInfo::Channel original_channel_;
+  };
 
   const std::string& name() const { return name_; }
   void set_name(const std::string& name) { name_ = name; }
 
   // Gets the platform the code is currently running on.
   static Platform GetCurrentPlatform();
 
   // Gets the Feature::Location value for the specified Extension::Location.
   static Location ConvertLocation(Extension::Location extension_location);
 
@@ skipping 66 matching lines @@
   Location location_;  // we only care about component/not-component now
   Platform platform_;  // we only care about chromeos/not-chromeos now
   int min_manifest_version_;
   int max_manifest_version_;
   chrome::VersionInfo::Channel channel_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_FEATURES_FEATURE_H_