Fixes crash in RemoteWindowTreeHostWin::HandleActivateDesktop

chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h

Index: chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h
diff --git a/chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h b/chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h
index f63605b954473dd2d7039f9868c3760054198bc5..50c6aed421ac4011804183e876ae1ecb806a4dd8 100644
--- a/chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h
+++ b/chrome/browser/metro_viewer/chrome_metro_viewer_process_host_aurawin.h
@@ -7,9 +7,25 @@
 
 #include "win8/viewer/metro_viewer_process_host.h"
 
+namespace base {
+class FilePath;
+}
+
+// Handles the activate desktop command for Metro Chrome Ash.   The |ash_exit|
+// parameter indicates whether the Ash process would be shutdown after
+// activating the desktop.
+void HandleActivateDesktop(const base::FilePath& shortcut, bool ash_exit);
+
 class ChromeMetroViewerProcessHost : public win8::MetroViewerProcessHost {
  public:
   ChromeMetroViewerProcessHost();
+  virtual ~ChromeMetroViewerProcessHost();
+
+  // Returns the singleton ChromeMetroViewerProcessHost instance. This may
+  // return NULL.
+  static ChromeMetroViewerProcessHost* instance() {
+    return instance_;
+  }
 
  private:
   // win8::MetroViewerProcessHost implementation
@@ -23,6 +39,8 @@ class ChromeMetroViewerProcessHost : public win8::MetroViewerProcessHost {
       const base::string16& search_string) OVERRIDE;
   virtual void OnWindowSizeChanged(uint32 width, uint32 height) OVERRIDE;
 
+  static ChromeMetroViewerProcessHost* instance_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeMetroViewerProcessHost);
 };