Support WebView in ash.

ash/shell.h

Index: ash/shell.h
===================================================================
--- ash/shell.h	(revision 131874)
+++ ash/shell.h	(working copy)
@@ -28,6 +28,10 @@
 class RootWindow;
 class Window;
 }
+namespace content {
+class BrowserContext;
+}
+
 namespace gfx {
 class Point;
 class Rect;
@@ -248,6 +252,11 @@
     return shadow_controller_.get();
   }
 
+  content::BrowserContext* browser_context() { return browser_context_; }
+  void set_browser_context(content::BrowserContext* browser_context) {
+    browser_context_ = browser_context;
+  }
+
  private:
   FRIEND_TEST_ALL_PREFIXES(RootWindowEventFilterTest, MouseEventCursors);
   FRIEND_TEST_ALL_PREFIXES(RootWindowEventFilterTest, TransformActivate);
@@ -345,6 +354,9 @@
   // |status_widget_|).
   scoped_ptr<SystemTray> tray_;
 
+  // Used by ash/shell.
+  content::BrowserContext* browser_context_;
+
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };