Fix overscroll glow when the FIP dialog is active

content/browser/android/overscroll_glow.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
 #define CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "content/browser/android/edge_effect.h"
 #include "ui/gfx/size_f.h"
 #include "ui/gfx/vector2d_f.h"
 
 class SkBitmap;
 
 namespace cc {
 class Layer;
 }
 
 namespace content {
 
 /* |OverscrollGlow| mirrors its Android counterpart, EdgeEffect.java.
  * Conscious tradeoffs were made to align this as closely as possible with the
  * original Android java version.
  */
 class OverscrollGlow {
  public:
-  static scoped_ptr<OverscrollGlow> Create();
+  // Create and initialize a new effect with the necessary resources.
+  // If |enabled| is false, the effect will be be deactivated until
+  // SetEnabled(true) is called.
+  // The caller should attach |root_layer| to the desired layer tree.
+  static scoped_ptr<OverscrollGlow> Create(bool enabled);
 
   // Force loading of any necessary resources.  This function is thread-safe.
   static void EnsureResources();
 
   ~OverscrollGlow();
 
+  // If false, the glow will be deactivated, and subsequent calls to
+  // OnOverscrolled or Animate will have no effect.
+  void SetEnabled(bool enabled);
+
+  // |overscroll| is the accumulated overscroll for the current gesture.
+  // |velocity| is the instantaneous velocity for the overscroll.
   void OnOverscrolled(base::TimeTicks current_time,
                       gfx::Vector2dF overscroll,
                       gfx::Vector2dF velocity);
+
   // Returns true if the effect still needs animation ticks.
   bool Animate(base::TimeTicks current_time);
-  void Finish();
 
   // Returns true if the effect needs animation ticks.
-  bool IsActive() const;
+  bool NeedsAnimate() const;
 
   // The root layer of the effect (not necessarily of the tree).
   scoped_refptr<cc::Layer> root_layer() const {
     return root_layer_;
   }
 
+  // Horizontal overscroll will be ignored when false.
   void set_horizontal_overscroll_enabled(bool enabled) {
     horizontal_overscroll_enabled_ = enabled;
   }
+  // Vertical overscroll will be ignored when false.
   void set_vertical_overscroll_enabled(bool enabled) {
     vertical_overscroll_enabled_ = enabled;
   }
-
+  // The size of the layer for which edges will be animated.
   void set_size(gfx::SizeF size) {
     size_ = size;
   }
 
  private:
   enum Axis { AXIS_X, AXIS_Y };
 
-  OverscrollGlow(const SkBitmap& edge, const SkBitmap& glow);
+  OverscrollGlow(bool enabled, const SkBitmap& edge, const SkBitmap& glow);
 
   void Pull(base::TimeTicks current_time,
             gfx::Vector2dF added_overscroll);
   void Absorb(base::TimeTicks current_time,
               gfx::Vector2dF velocity,
               gfx::Vector2dF overscroll,
               gfx::Vector2dF old_overscroll);
 
   void Release(base::TimeTicks current_time);
   void Release(Axis axis, base::TimeTicks current_time);
 
   EdgeEffect* GetOppositeEdge(int edge_index);
 
   scoped_ptr<EdgeEffect> edge_effects_[EdgeEffect::EDGE_COUNT];
 
+  bool enabled_;
   gfx::SizeF size_;
   gfx::Vector2dF old_overscroll_;
   gfx::Vector2dF old_velocity_;
   bool horizontal_overscroll_enabled_;
   bool vertical_overscroll_enabled_;
 
   scoped_refptr<cc::Layer> root_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_SCROLL_GLOW_H_