Use scroll-boundary-behavior to control overscroll-refresh/glow on android.

ui/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 UI_ANDROID_OVERSCROLL_GLOW_H_
 #define UI_ANDROID_OVERSCROLL_GLOW_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 22 matching lines @@
 /* |OverscrollGlow| mirrors its Android counterpart, OverscrollGlow.java.
  * Conscious tradeoffs were made to align this as closely as possible with the
  * original Android Java version.
  */
 class UI_ANDROID_EXPORT OverscrollGlow {
  public:
   // |client| must be valid for the duration of the effect's lifetime.
   // The effect is enabled by default, but will remain dormant until the first
   // overscroll event.
   explicit OverscrollGlow(OverscrollGlowClient* client);
+  // This constructor is for test only.

[majidvp, 2017/07/12 21:04:21]

Why is this needed? Can't we just use the above constructor
and pass in null for client?

Presumably in your test client_ is never used otherwise they
would crash. So it should be fair to just move the DCHECK to
methods that actually use client_ instead of constructor.

[sunyunjia, 2017/07/19 20:44:12]

Done.

+  OverscrollGlow();
   ~OverscrollGlow();
 
   // Called when the root content layer overscrolls.
   // |accumulated_overscroll| and |overscroll_delta| are in device pixels, while
   // |velocity| is in device pixels / second.
   // |overscroll_location| is the coordinate of the causal overscrolling event.
   // Returns true if the effect still needs animation ticks.
-  bool OnOverscrolled(base::TimeTicks current_time,
-                      const gfx::Vector2dF& accumulated_overscroll,
-                      gfx::Vector2dF overscroll_delta,
-                      gfx::Vector2dF velocity,
-                      const gfx::Vector2dF& overscroll_location);
+  virtual bool OnOverscrolled(base::TimeTicks current_time,
+                              const gfx::Vector2dF& accumulated_overscroll,
+                              gfx::Vector2dF overscroll_delta,
+                              gfx::Vector2dF velocity,
+                              const gfx::Vector2dF& overscroll_location);
 
   // Returns true if the effect still needs animation ticks, with effect layers
   // attached to |parent_layer| if necessary.
   // Note: The effect will detach itself when no further animation is required.
   bool Animate(base::TimeTicks current_time, cc::Layer* parent_layer);
 
   // Update the effect according to the most recent display parameters,
   // Note: All dimensions are in device pixels.
   void OnFrameUpdated(const gfx::SizeF& viewport_size,
                       const gfx::SizeF& content_size,
@@ skipping 39 matching lines @@
   bool allow_vertical_overscroll_;
 
   scoped_refptr<cc::Layer> root_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_OVERSCROLL_GLOW_H_