Remove canScroll from WebMouseWheelEvent as it is unused now.

content/common/input/web_input_event_traits.cc

 // Copyright 2013 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/common/input/web_input_event_traits.h"
 
 #include <bitset>
 #include <limits>
 
 #include "base/logging.h"
@@ skipping 37 matching lines @@
                 event.windowX,
                 event.windowY,
                 event.globalX,
                 event.globalY,
                 event.movementX,
                 event.movementY,
                 event.clickCount);
 }
 
 void ApppendEventDetails(const WebMouseWheelEvent& event, std::string* result) {
-  StringAppendF(result,
-                "{\n Delta: (%f, %f)\n WheelTicks: (%f, %f)\n Accel: (%f, %f)\n"
-                " ScrollByPage: %d\n HasPreciseScrollingDeltas: %d\n"
-                " Phase: (%d, %d)\n CanRubberband: (%d, %d)\n CanScroll: %d\n}",
-                event.deltaX,
-                event.deltaY,
-                event.wheelTicksX,
-                event.wheelTicksY,
-                event.accelerationRatioX,
-                event.accelerationRatioY,
-                event.scrollByPage,
-                event.hasPreciseScrollingDeltas,
-                event.phase,
-                event.momentumPhase,
-                event.canRubberbandLeft,
-                event.canRubberbandRight,
-                event.canScroll);
+  StringAppendF(
+      result,
+      "{\n Delta: (%f, %f)\n WheelTicks: (%f, %f)\n Accel: (%f, %f)\n"
+      " ScrollByPage: %d\n HasPreciseScrollingDeltas: %d\n"
+      " Phase: (%d, %d)\n CanRubberband: (%d, %d)\n}",
+      event.deltaX, event.deltaY, event.wheelTicksX, event.wheelTicksY,
+      event.accelerationRatioX, event.accelerationRatioY, event.scrollByPage,
+      event.hasPreciseScrollingDeltas, event.phase, event.momentumPhase,
+      event.canRubberbandLeft, event.canRubberbandRight);
 }
 
 void ApppendEventDetails(const WebGestureEvent& event, std::string* result) {
   StringAppendF(result,
                 "{\n Pos: (%d, %d)\n GlobalPos: (%d, %d)\n SourceDevice: %d\n"
                 " RawData: (%f, %f, %f, %f, %d)\n}",
                 event.x,
                 event.y,
                 event.globalX,
                 event.globalY,
@@ skipping 61 matching lines @@
   event->movementY += y;
 }
 
 bool CanCoalesce(const WebMouseWheelEvent& event_to_coalesce,
                  const WebMouseWheelEvent& event) {
   return event.modifiers == event_to_coalesce.modifiers &&
          event.scrollByPage == event_to_coalesce.scrollByPage &&
          event.phase == event_to_coalesce.phase &&
          event.momentumPhase == event_to_coalesce.momentumPhase &&
          event.hasPreciseScrollingDeltas ==
-             event_to_coalesce.hasPreciseScrollingDeltas &&
-         event.canScroll == event_to_coalesce.canScroll;
+             event_to_coalesce.hasPreciseScrollingDeltas;
 }
 
 float GetUnacceleratedDelta(float accelerated_delta, float acceleration_ratio) {
   return accelerated_delta * acceleration_ratio;
 }
 
 float GetAccelerationRatio(float accelerated_delta, float unaccelerated_delta) {
   if (unaccelerated_delta == 0.f || accelerated_delta == 0.f)
     return 1.f;
   return unaccelerated_delta / accelerated_delta;
@@ skipping 350 matching lines @@
              WebInputEvent::Blocking;
 
     // Touch move events may be non-blocking but are always explicitly
     // acknowledge by the renderer so they block the event stream.
     case WebInputEvent::TouchMove:
     default:
       return true;
   }
 }
 
+bool WebInputEventTraits::CanCauseScroll(
+    const blink::WebMouseWheelEvent& event) {
+#if defined(USE_AURA)
+  // Scroll events generated from the mouse wheel when the control key is held
+  // don't trigger scrolling. Instead, they may cause zooming.
+  return event.hasPreciseScrollingDeltas ||
+         (event.modifiers & blink::WebInputEvent::ControlKey) == 0;
+#else
+  return true;
+#endif
+}
+
 uint32_t WebInputEventTraits::GetUniqueTouchEventId(
     const WebInputEvent& event) {
   if (WebInputEvent::isTouchEventType(event.type)) {
     return static_cast<const WebTouchEvent&>(event).uniqueTouchEventId;
   }
   return 0U;
 }
 
 }  // namespace content