Explicitly suppress scrolling for wheel events that will trigger zooming

content/shell/renderer/test_runner/event_sender.cc

 // Copyright 2014 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/shell/renderer/test_runner/event_sender.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "content/public/common/page_zoom.h"
@@ skipping 2189 matching lines @@
   }
   double vertical;
   if (!args->GetNext(&vertical)) {
     args->ThrowError();
     return;
   }
 
   bool paged = false;
   bool has_precise_scrolling_deltas = false;
   int modifiers = 0;
-  if (!args->PeekNext().IsEmpty()) {
-    args->GetNext(&paged);
-    if (!args->PeekNext().IsEmpty()) {
-      args->GetNext(&has_precise_scrolling_deltas);
-      if (!args->PeekNext().IsEmpty())
-        modifiers = GetKeyModifiersFromV8(args->PeekNext());
-    }
-  }
+  bool can_scroll = true;
+  if (args->PeekNext().IsEmpty())
+    return;
+  args->GetNext(&paged);
+  if (args->PeekNext().IsEmpty())
+    return;
+  args->GetNext(&has_precise_scrolling_deltas);
+  if (args->PeekNext().IsEmpty())
+    return;
+  v8::Handle<v8::Value> value;
+  args->GetNext(&value);
+  modifiers = GetKeyModifiersFromV8(value);
+  if (args->PeekNext().IsEmpty())
+    return;
+  args->GetNext(&can_scroll);
 
   InitMouseEvent(WebInputEvent::MouseWheel,
                  pressed_button_,
                  last_mouse_pos_,
                  GetCurrentEventTimeSec(),
                  click_count_,
                  modifiers,
                  event);
   event->wheelTicksX = static_cast<float>(horizontal);
   event->wheelTicksY = static_cast<float>(vertical);
   event->deltaX = event->wheelTicksX;
   event->deltaY = event->wheelTicksY;
   event->scrollByPage = paged;
   event->hasPreciseScrollingDeltas = has_precise_scrolling_deltas;
-
+  event->canScroll = can_scroll;
   if (continuous) {
     event->wheelTicksX /= kScrollbarPixelsPerTick;
     event->wheelTicksY /= kScrollbarPixelsPerTick;
   } else {
     event->deltaX *= kScrollbarPixelsPerTick;
     event->deltaY *= kScrollbarPixelsPerTick;
   }
 }
 
 void EventSender::FinishDragAndDrop(const WebMouseEvent& e,
@@ skipping 93 matching lines @@
 
 bool EventSender::HandleInputEventOnViewOrPopup(const WebInputEvent& event) {
   if (WebPagePopup* popup = view_->pagePopup()) {
     if (!WebInputEvent::isKeyboardEventType(event.type))
       return popup->handleInputEvent(event);
   }
   return view_->handleInputEvent(event);
 }
 
 }  // namespace content