Remove canScroll from WebMouseWheelEvent as it is unused now.

content/browser/web_contents/web_contents_impl.cc

 // 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.
 
 #include "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 1721 matching lines @@
 bool WebContentsImpl::HandleWheelEvent(
     const blink::WebMouseWheelEvent& event) {
 #if !defined(OS_MACOSX)
   // On platforms other than Mac, control+mousewheel may change zoom. On Mac,
   // this isn't done for two reasons:
   //   -the OS already has a gesture to do this through pinch-zoom
   //   -if a user starts an inertial scroll, let's go, and presses control
   //      (i.e. control+tab) then the OS's buffered scroll events will come in
   //      with control key set which isn't what the user wants
   if (delegate_ && event.wheelTicksY &&
-      (event.modifiers & blink::WebInputEvent::ControlKey) &&
-      !event.canScroll) {
+      !WebInputEventTraits::CanCauseScroll(event)) {
     // Count only integer cumulative scrolls as zoom events; this handles
     // smooth scroll and regular scroll device behavior.
     zoom_scroll_remainder_ += event.wheelTicksY;
     int whole_zoom_scroll_remainder_ = std::lround(zoom_scroll_remainder_);
     zoom_scroll_remainder_ -= whole_zoom_scroll_remainder_;
     if (whole_zoom_scroll_remainder_ != 0) {
       delegate_->ContentsZoomChange(whole_zoom_scroll_remainder_ > 0);
     }
     return true;
   }
@@ skipping 3373 matching lines @@
   for (RenderViewHost* render_view_host : render_view_host_set)
     render_view_host->OnWebkitPreferencesChanged();
 }
 
 void WebContentsImpl::SetJavaScriptDialogManagerForTesting(
     JavaScriptDialogManager* dialog_manager) {
   dialog_manager_ = dialog_manager;
 }
 
 }  // namespace content