Fix OverscrollWindowDelegate to not dispatch superfluous OverscrollModeChange events

content/browser/web_contents/aura/overscroll_window_delegate_unittest.cc

 // Copyright 2015 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.
 
 #include "content/browser/web_contents/aura/overscroll_window_delegate.h"
 
 #include "content/browser/renderer_host/overscroll_controller_delegate.h"
 #include "content/public/browser/overscroll_configuration.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/test/aura_test_base.h"
 #include "ui/aura/window.h"
 #include "ui/events/gesture_detection/gesture_configuration.h"
 #include "ui/events/test/event_generator.h"
 
 namespace content {
 
 namespace {
 const int kTestWindowWidth = 600;
 }
 
 class OverscrollWindowDelegateTest : public aura::test::AuraTestBase,
                                      public OverscrollControllerDelegate {
  public:
   OverscrollWindowDelegateTest()
       : window_(nullptr),
         overscroll_complete_(false),
         overscroll_started_(false),
+        mode_changed_(false),
         current_mode_(OVERSCROLL_NONE),
         touch_start_threshold_(content::GetOverscrollConfig(
             content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHSCREEN)),
         touch_complete_threshold_(content::GetOverscrollConfig(
             content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_COMPLETE)) {
   }
 
   ~OverscrollWindowDelegateTest() override {}
 
   void Reset() {
     overscroll_complete_ = false;
     overscroll_started_ = false;
+    mode_changed_ = false;
     current_mode_ = OVERSCROLL_NONE;
     window_.reset(CreateNormalWindow(
         0, root_window(), new OverscrollWindowDelegate(this, gfx::Image())));
     window_->SetBounds(gfx::Rect(0, 0, kTestWindowWidth, kTestWindowWidth));
   }
 
   // Accessors.
   aura::Window* window() { return window_.get(); }
 
   bool overscroll_complete() { return overscroll_complete_; }
   bool overscroll_started() { return overscroll_started_; }
+  bool mode_changed() { return mode_changed_; }
 
   OverscrollMode current_mode() { return current_mode_; }
 
   const float touch_start_threshold() {
     return touch_start_threshold_;
   }
 
   const float touch_complete_threshold() {
     return kTestWindowWidth * touch_complete_threshold_;
   }
@@ skipping 21 matching lines @@
   bool OnOverscrollUpdate(float delta_x, float delta_y) override {
     return true;
   }
 
   void OnOverscrollComplete(OverscrollMode overscroll_mode) override {
     overscroll_complete_ = true;
   }
 
   void OnOverscrollModeChange(OverscrollMode old_mode,
                               OverscrollMode new_mode) override {
+    mode_changed_ = true;
     current_mode_ = new_mode;
     if (current_mode_ != OVERSCROLL_NONE)
       overscroll_started_ = true;
   }
 
   // Window in which the overscroll window delegate is installed.
   scoped_ptr<aura::Window> window_;
 
   // State flags.
   bool overscroll_complete_;
   bool overscroll_started_;
-
+  bool mode_changed_;
   OverscrollMode current_mode_;
 
   // Config defined constants.
   const float touch_start_threshold_;
   const float touch_complete_threshold_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollWindowDelegateTest);
 };
 
 // Tests that the basic overscroll gesture works and sends updates to the
@@ skipping 46 matching lines @@
   EXPECT_EQ(delegate->overscroll_mode_, OVERSCROLL_NONE);
 
   // Slide the touch to the left.
   generator.MoveTouch(gfx::Point(0, 0));
   EXPECT_EQ(delegate->overscroll_mode_, OVERSCROLL_WEST);
 
   // Complete the gesture.
   generator.ReleaseTouch();
   EXPECT_EQ(delegate->overscroll_mode_, OVERSCROLL_NONE);
   EXPECT_TRUE(overscroll_complete());
+
+  // Generate a mouse events which normally cancel the overscroll. Confirm
+  // that superfluous mode changed events are not dispatched.
+  Reset();
+  generator.PressLeftButton();
+  generator.MoveMouseTo(gfx::Point(10, 10));
+  EXPECT_FALSE(mode_changed());
 }
 
 // Tests that the overscroll does not start until the gesture gets past a
 // particular threshold.
 TEST_F(OverscrollWindowDelegateTest, OverscrollThreshold) {
   ui::test::EventGenerator generator(root_window());
 
   // Start an OVERSCROLL_EAST gesture.
   generator.GestureScrollSequence(gfx::Point(0, 0),
                                   gfx::Point(touch_start_threshold(), 0),
@@ skipping 53 matching lines @@
   EXPECT_EQ(current_mode(), OVERSCROLL_NONE);
   EXPECT_FALSE(overscroll_complete());
 
   // We should be able to restart the overscroll without lifting the finger.
   generator.MoveTouch(gfx::Point(touch_x + touch_start_threshold() + 1, 0));
   EXPECT_EQ(current_mode(), OVERSCROLL_EAST);
   EXPECT_FALSE(overscroll_complete());
 }
 
 }  // namespace content