Revert of Refactor GestureNavigation to eliminate code redundancy

content/browser/web_contents/aura/overscroll_navigation_overlay.h

Index: content/browser/web_contents/aura/overscroll_navigation_overlay.h
diff --git a/content/browser/web_contents/aura/overscroll_navigation_overlay.h b/content/browser/web_contents/aura/overscroll_navigation_overlay.h
index d0d562ec0b5b157fc664ab587f3ced7a9005fd63..6e0ec07dc87342150daeac07a7ac1ddd173b5f81 100644
--- a/content/browser/web_contents/aura/overscroll_navigation_overlay.h
+++ b/content/browser/web_contents/aura/overscroll_navigation_overlay.h
@@ -7,56 +7,34 @@
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
-#include "content/browser/web_contents/aura/overscroll_window_animation.h"
-#include "content/browser/web_contents/web_contents_view_aura.h"
+#include "content/browser/web_contents/aura/window_slider.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/web_contents_observer.h"
-#include "ui/gfx/image/image.h"
 
 struct ViewHostMsg_UpdateRect_Params;
 
+namespace aura_extra {
+class ImageWindowDelegate;
+}
+
 namespace content {
 
-class OverscrollWindowDelegate;
+class ImageLayerDelegate;
 class OverscrollNavigationOverlayTest;
-class ScopedLayerClippingSetting;
 
 // When a history navigation is triggered at the end of an overscroll
 // navigation, it is necessary to show the history-screenshot until the page is
-// done navigating and painting. This class accomplishes this by calling the
-// navigation and creating, showing and destroying the screenshot window on top
-// of the page until the page has completed loading and painting. When the
-// overscroll completes, this screenshot window is returned by
-// OnOverscrollComplete and |window_| is set to own it.
-// There are two overscroll cases, for the first one the main window is the web
-// contents window. At this stage, |window_| is null. The second case is
-// triggered if the user overscrolls after |window_| is set, before the page
-// finishes loading. When this happens, |window_| is the main window.
+// done navigating and painting. This class accomplishes this by showing the
+// screenshot window on top of the page until the page has completed loading and
+// painting.
 class CONTENT_EXPORT OverscrollNavigationOverlay
     : public WebContentsObserver,
-      public OverscrollWindowAnimation::Delegate {
+      public WindowSlider::Delegate {
  public:
-  enum NavigationDirection { FORWARD, BACK, NONE };
-
-  OverscrollNavigationOverlay(WebContentsImpl* web_contents,
-                              aura::Window* web_contents_window);
-
+  explicit OverscrollNavigationOverlay(WebContentsImpl* web_contents);
   ~OverscrollNavigationOverlay() override;
 
-  // Returns a pointer to the relay delegate we own.
-  OverscrollControllerDelegate* relay_delegate() { return owa_.get(); }
-
- private:
-  class ScopedLayerClippingSetting;
-
-  friend class OverscrollNavigationOverlayTest;
-  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest, WithScreenshot);
-  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest, WithoutScreenshot);
-  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest, CannotNavigate);
-  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest, CancelNavigation);
-  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
-                           CancelAfterSuccessfulNavigation);
-  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest, OverlayWindowSwap);
+  bool has_window() const { return !!window_.get(); }
 
   // Resets state and starts observing |web_contents_| for page load/paint
   // updates. This function makes sure that the screenshot window is stacked
@@ -66,39 +44,62 @@
   // otherwise the overlay may be dismissed prematurely.
   void StartObserving();
 
+  // Sets the screenshot window and the delegate. This takes ownership of
+  // |window|.
+  // Note that aura_extra::ImageWindowDelegate manages its own lifetime, so this
+  // function does not take ownership of |delegate|.
+  void SetOverlayWindow(scoped_ptr<aura::Window> window,
+                        aura_extra::ImageWindowDelegate* delegate);
+
+ private:
+  friend class OverscrollNavigationOverlayTest;
+  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
+                           FirstVisuallyNonEmptyPaint_NoImage);
+  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
+                           FirstVisuallyNonEmptyPaint_WithImage);
+  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
+                           LoadUpdateWithoutNonEmptyPaint);
+  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
+                           MultiNavigation_LoadingUpdate);
+  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
+                           MultiNavigation_PaintUpdate);
+
+  enum SlideDirection {
+    SLIDE_UNKNOWN,
+    SLIDE_BACK,
+    SLIDE_FRONT
+  };
+
   // Stop observing the page and start the final overlay fade-out animation if
-  // there's no active overscroll window animation.
+  // a window-slide isn't in progress and either the page has been painted or
+  // the page-load has completed.
   void StopObservingIfDone();
 
-  // Creates a window that shows a history-screenshot and is stacked relative to
-  // the current overscroll |direction_| with the given |bounds|.
-  scoped_ptr<aura::Window> CreateOverlayWindow(const gfx::Rect& bounds);
+  // Creates a layer to be used for window-slide. |offset| is the offset of the
+  // NavigationEntry for the screenshot image to display.
+  ui::Layer* CreateSlideLayer(int offset);
 
-  // Returns an image with the history-screenshot for the previous or next page,
-  // according to the given |direction|.
-  const gfx::Image GetImageForDirection(NavigationDirection direction) const;
-
-  // Overridden from OverscrollWindowAnimation::Delegate:
-  scoped_ptr<aura::Window> CreateFrontWindow(const gfx::Rect& bounds) override;
-  scoped_ptr<aura::Window> CreateBackWindow(const gfx::Rect& bounds) override;
-  aura::Window* GetMainWindow() const override;
-  void OnOverscrollCompleting() override;
-  void OnOverscrollCompleted(scoped_ptr<aura::Window> window) override;
-  void OnOverscrollCancelled() override;
+  // Overridden from WindowSlider::Delegate:
+  ui::Layer* CreateBackLayer() override;
+  ui::Layer* CreateFrontLayer() override;
+  void OnWindowSlideCompleting() override;
+  void OnWindowSlideCompleted(scoped_ptr<ui::Layer> layer) override;
+  void OnWindowSlideAborted() override;
+  void OnWindowSliderDestroyed() override;
 
   // Overridden from WebContentsObserver:
   void DidFirstVisuallyNonEmptyPaint() override;
   void DidStopLoading() override;
 
-  // The current overscroll direction.
-  NavigationDirection direction_;
-
-  // The web contents that are being navigated.
+  // The WebContents which is being navigated.
   WebContentsImpl* web_contents_;
 
-  // The overlay window that shows a screenshot during an overscroll gesture and
-  // handles overscroll events during the second overscroll case.
+  // The screenshot overlay window.
   scoped_ptr<aura::Window> window_;
+
+  // This is the WindowDelegate of |window_|. The delegate manages its own
+  // lifetime (destroys itself when |window_| is destroyed).
+  aura_extra::ImageWindowDelegate* image_delegate_;
 
   bool loading_complete_;
   bool received_paint_update_;
@@ -108,15 +109,19 @@
   // when the relevant page loads and paints.
   GURL pending_entry_url_;
 
-  // Manages the overscroll animations.
-  scoped_ptr<OverscrollWindowAnimation> owa_;
+  // The |WindowSlider| that allows sliding history layers while the page is
+  // being reloaded.
+  scoped_ptr<WindowSlider> window_slider_;
 
-  // The window that hosts the web contents.
-  aura::Window* web_contents_window_;
+  // Layer to be used for the final overlay fadeout animation when the overlay
+  // is being dismissed.
+  scoped_ptr<ui::Layer> overlay_dismiss_layer_;
 
-  // Scoped clipping settings for the contents layer and its parent.
-  scoped_ptr<ScopedLayerClippingSetting> contents_layer_settings_;
-  scoped_ptr<ScopedLayerClippingSetting> contents_layer_parent_settings_;
+  // The direction of the in-progress slide (if any).
+  SlideDirection slide_direction_;
+
+  // The LayerDelegate used for the back/front layers during a slide.
+  scoped_ptr<ImageLayerDelegate> layer_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
 };