Implemented new channel switcher UI.

chrome/browser/ui/webui/help/help_handler.h

Index: chrome/browser/ui/webui/help/help_handler.h
diff --git a/chrome/browser/ui/webui/help/help_handler.h b/chrome/browser/ui/webui/help/help_handler.h
index 397c02343d6138cd08418b6ebe544499393fd6c1..0f25dab1f4d15d3714c5e23cd81bb57492a7f70b 100644
--- a/chrome/browser/ui/webui/help/help_handler.h
+++ b/chrome/browser/ui/webui/help/help_handler.h
@@ -60,7 +60,10 @@ class HelpHandler : public content::WebUIMessageHandler,
 
 #if defined(OS_CHROMEOS)
   // Sets the release track version.
-  void SetReleaseTrack(const base::ListValue* args);
+  void SetChannel(const base::ListValue* args);
+
+  // Performs relaunch and powerwash.
+  void RelaunchAndPowerwash(const base::ListValue* args);
 #endif
 
   // Callback method which forwards status updates to the page.
@@ -76,7 +79,8 @@ class HelpHandler : public content::WebUIMessageHandler,
   // Callbacks from VersionLoader.
   void OnOSVersion(const std::string& version);
   void OnOSFirmware(const std::string& firmware);
-  void OnReleaseChannel(const std::string& channel);
+  void OnCurrentChannel(const std::string& channel);
+  void OnTargetChannel(const std::string& channel);
 
   void ProcessLsbFileInfo(
       base::PlatformFileError rv, const base::PlatformFileInfo& file_info);