Introduce new WebApp header style for hosted apps and fizzy apps on ash.

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h

Index: chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
diff --git a/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h b/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
index ef012383212b14c89687aa26731791567dfa50e9..f27b30bad3b46029178b9247ff2471aa2e954c31 100644
--- a/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
+++ b/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
@@ -8,6 +8,7 @@
 #include "ash/shell_observer.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "chrome/browser/command_observer.h"
 #include "chrome/browser/ui/views/frame/browser_non_client_frame_view.h"
 #include "chrome/browser/ui/views/tab_icon_view_model.h"
 
@@ -15,6 +16,7 @@ class TabIconView;
 
 namespace ash {
 class FrameBorderHitTestController;
+class FrameCaptionButton;
 class FrameCaptionButtonContainerView;
 class HeaderPainter;
 }
@@ -23,10 +25,11 @@ class ImageButton;
 class ToggleImageButton;
 }
 
-class BrowserNonClientFrameViewAsh
-    : public BrowserNonClientFrameView,
-      public ash::ShellObserver,
-      public chrome::TabIconViewModel {
+class BrowserNonClientFrameViewAsh : public BrowserNonClientFrameView,
+                                     public ash::ShellObserver,
+                                     public chrome::TabIconViewModel,
+                                     public CommandObserver,
+                                     public views::ButtonListener {
  public:
   static const char kViewClassName[];
 
@@ -67,6 +70,13 @@ class BrowserNonClientFrameViewAsh
   virtual bool ShouldTabIconViewAnimate() const OVERRIDE;
   virtual gfx::ImageSkia GetFaviconForTabIconView() OVERRIDE;
 
+  // CommandObserver:
+  virtual void EnabledStateChangedForCommand(int id, bool enabled) OVERRIDE;
+
+  // views::ButtonListener:
+  virtual void ButtonPressed(views::Button* sender,
+                             const ui::Event& event) OVERRIDE;
+
  private:
   FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshTest, WindowHeader);
   FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshTest,
@@ -97,6 +107,11 @@ class BrowserNonClientFrameViewAsh
   // scheme than browser windows.
   bool UsePackagedAppHeaderStyle() const;
 
+  // Returns true if the header should be painted with a WebApp header style.
+  // The WebApp header style has a back button and title along with the usual
+  // accoutrements.
+  bool UseWebAppHeaderStyle() const;
+
   // Layout the incognito icon.
   void LayoutAvatar();
 
@@ -114,9 +129,15 @@ class BrowserNonClientFrameViewAsh
   // the packaged app header style.
   void PaintContentEdge(gfx::Canvas* canvas);
 
+  // Update the state of the back button.
+  void UpdateBackButtonState(bool enabled);
+
   // View which contains the window controls.
   ash::FrameCaptionButtonContainerView* caption_button_container_;
 
+  // View which contains the back button for WebApp style header.
+  ash::FrameCaptionButton* webapp_back_button_;
+
   // For popups, the window icon.
   TabIconView* window_icon_;