ui: Cleanup class/struct forward declarations

ash/common/wm_window.h

Index: ash/common/wm_window.h
diff --git a/ash/common/wm_window.h b/ash/common/wm_window.h
index 069899a30dfae88174f8943ae4a8a80447652861..3871d2f01262bbedf8a3fff432a015187d2719a3 100644
--- a/ash/common/wm_window.h
+++ b/ash/common/wm_window.h
@@ -14,7 +14,6 @@
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/compositor/layer_animation_element.h"
-#include "ui/gfx/image/image_skia.h"
 #include "ui/wm/core/window_animations.h"
 #include "ui/wm/public/window_types.h"
 
@@ -138,12 +137,6 @@ class ASH_EXPORT WmWindow {
   virtual void SetColorProperty(WmWindowProperty key, SkColor value) = 0;
   virtual int GetIntProperty(WmWindowProperty key) = 0;
   virtual void SetIntProperty(WmWindowProperty key, int value) = 0;
-  virtual std::string GetStringProperty(WmWindowProperty key) = 0;
-  virtual void SetStringProperty(WmWindowProperty key,
-                                 const std::string& value) = 0;
-
-  virtual gfx::ImageSkia GetWindowIcon() = 0;
-  virtual gfx::ImageSkia GetAppIcon() = 0;
 
   wm::WindowState* GetWindowState() {
     return const_cast<wm::WindowState*>(
@@ -176,9 +169,6 @@ class ASH_EXPORT WmWindow {
   virtual const WmWindow* GetTransientParent() const = 0;
   virtual Windows GetTransientChildren() = 0;
 
-  // Moves this to the display where |event| occurred; returns true if moved.
-  virtual bool MoveToEventRoot(const ui::Event& event) = 0;
-
   virtual void SetLayoutManager(
       std::unique_ptr<WmLayoutManager> layout_manager) = 0;
   virtual WmLayoutManager* GetLayoutManager() = 0;