Remove remote tree host and some related input and metro_driver code

chrome/browser/browser_process_platform_part_aurawin.h

Index: chrome/browser/browser_process_platform_part_aurawin.h
diff --git a/chrome/browser/browser_process_platform_part_aurawin.h b/chrome/browser/browser_process_platform_part_aurawin.h
index 06dec47e475b6811f060af2638e4002b0732199c..0edc73dda858b6dd5c4af6a514753b56c4c4cd28 100644
--- a/chrome/browser/browser_process_platform_part_aurawin.h
+++ b/chrome/browser/browser_process_platform_part_aurawin.h
@@ -12,17 +12,12 @@
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
-class ChromeMetroViewerProcessHost;
-
 class BrowserProcessPlatformPart : public BrowserProcessPlatformPartBase,
                                    public content::NotificationObserver {
  public:
   BrowserProcessPlatformPart();
   ~BrowserProcessPlatformPart() override;
 
-  // Invoked when the ASH metro viewer process on Windows 8 exits.
-  void OnMetroViewerProcessTerminated();
-
   // Overridden from BrowserProcessPlatformPartBase:
   void PlatformSpecificCommandLineProcessing(
       const base::CommandLine& command_line) override;
@@ -33,10 +28,6 @@ class BrowserProcessPlatformPart : public BrowserProcessPlatformPartBase,
                const content::NotificationDetails& details) override;
 
  private:
-  // Hosts the channel for the Windows 8 metro viewer process which runs in
-  // the ASH environment.
-  scoped_ptr<ChromeMetroViewerProcessHost> metro_viewer_process_host_;
-
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserProcessPlatformPart);