Wheel scroll latching enabled behind flag.

content/browser/renderer_host/input/mouse_wheel_event_queue_unittest.cc

 // Copyright 2016 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/renderer_host/input/mouse_wheel_event_queue.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
@@ skipping 12 matching lines @@
 using blink::WebInputEvent;
 using blink::WebMouseWheelEvent;
 
 namespace content {
 namespace {
 
 const float kWheelScrollX = 10;
 const float kWheelScrollY = 12;
 const float kWheelScrollGlobalX = 50;
 const float kWheelScrollGlobalY = 72;
-const int64_t kScrollEndTimeoutMs = 100;
+const bool kTouchpadAndWheelScrollLatching = true;
+const int64_t kScrollEndTimeoutMs = kTouchpadAndWheelScrollLatching ? 100 : 0;
 
 base::TimeDelta DefaultScrollEndTimeoutDelay() {
   return base::TimeDelta::FromMilliseconds(kScrollEndTimeoutMs);
 }
 
 #define EXPECT_GESTURE_SCROLL_BEGIN_IMPL(event)              \
   EXPECT_EQ(WebInputEvent::GestureScrollBegin, event->type); \
   EXPECT_EQ(kWheelScrollX, event->x);                        \
   EXPECT_EQ(kWheelScrollY, event->y);                        \
   EXPECT_EQ(kWheelScrollGlobalX, event->globalX);            \
@@ skipping 95 matching lines @@
   EXPECT_EQ(WebInputEvent::MouseWheel, event->type);
 
 }  // namespace
 
 class MouseWheelEventQueueTest : public testing::Test,
                                  public MouseWheelEventQueueClient {
  public:
   MouseWheelEventQueueTest()
       : acked_event_count_(0),
         last_acked_event_state_(INPUT_EVENT_ACK_STATE_UNKNOWN) {
-    queue_.reset(new MouseWheelEventQueue(this, kScrollEndTimeoutMs));
+    queue_.reset(
+        new MouseWheelEventQueue(this, kTouchpadAndWheelScrollLatching));

[dtapuska, 2016/07/25 22:31:07]

should this be a parameterized test? that it runs with it enabled and not
enabled?

[tdresser, 2016/07/26 12:19:00]

+1!
(https://github.com/google/googletest/blob/master/googletest/docs/AdvancedGuid...)

[sahel, 2016/07/26 21:20:13]

Done.

   }
 
   ~MouseWheelEventQueueTest() override {}
 
   // MouseWheelEventQueueClient
   void SendMouseWheelEventImmediately(
       const MouseWheelEventWithLatencyInfo& event) override {
     WebMouseWheelEvent* cloned_event = new WebMouseWheelEvent();
     std::unique_ptr<WebInputEvent> cloned_event_holder(cloned_event);
     *cloned_event = event.event;
@@ skipping 392 matching lines @@
   EXPECT_EQ(1U, GetAndResetAckedEventCount());
   EXPECT_EQ(2U, all_sent_events().size());
   EXPECT_GESTURE_SCROLL_BEGIN(sent_gesture_event(0));
   EXPECT_GESTURE_SCROLL_UPDATE(sent_gesture_event(1));
   EXPECT_EQ(0U, sent_gesture_event(1)->data.scrollUpdate.deltaX);
   EXPECT_EQ(1U, sent_gesture_event(1)->data.scrollUpdate.deltaY);
   EXPECT_EQ(2U, GetAndResetSentEventCount());
 }
 
 }  // namespace content