Explicitly suppress scrolling for wheel events that will trigger zooming

content/browser/renderer_host/render_widget_host_view_aura_unittest.cc

Index: content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
index 2335dc08c252d41b280525c12cc4aa8b1344bbf2..b2290ef74895d7920f7505d73d170bc7eafdb1b4 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
@@ -308,6 +308,15 @@ class MockWindowObserver : public aura::WindowObserver {
   MOCK_METHOD2(OnDelegatedFrameDamage, void(aura::Window*, const gfx::Rect&));
 };
 
+const WebInputEvent* GetInputEventFromMessage(const IPC::Message& message) {
+  PickleIterator iter(message);
+  const char* data;
+  int data_length;
+  if (!message.ReadData(&iter, &data, &data_length))
+    return NULL;
+  return reinterpret_cast<const WebInputEvent*>(data);
+}
+
 }  // namespace
 
 class RenderWidgetHostViewAuraTest : public testing::Test {
@@ -3000,4 +3009,25 @@ TEST_F(RenderWidgetHostViewAuraTest, KeyEvent) {
   }
 }
 
+TEST_F(RenderWidgetHostViewAuraTest, SetCanScrollForWebMouseWheelEvent) {
+  view_->InitAsChild(NULL);
+  view_->Show();
+
+  sink_->ClearMessages();
+
+  // Simulates the mouse wheel event.
+  ui::MouseWheelEvent event(gfx::Vector2d(1, 1),
+                             gfx::Point(), gfx::Point(),
+                             ui::EF_CONTROL_DOWN, 0);
+  view_->OnMouseEvent(&event);
+
+  const WebInputEvent* input_event =
+      GetInputEventFromMessage(*sink_->GetMessageAt(0));
+  const WebMouseWheelEvent* wheel_event =
+      static_cast<const WebMouseWheelEvent*>(input_event);
+  // Check if the canScroll set to false when ctrl-scroll is generated from
+  // mouse wheel event.
+  EXPECT_FALSE(wheel_event->canScroll);

[Rick Byers, 2014/12/18 15:18:14]

Great, this is the key case you want to test.  But you should also verify that
you get TRUE when modifiers doesn't have CONTROL, and when it does but you have
precise deltas.  Then you will have tested all the important cases.

[lanwei, 2014/12/19 02:55:44]

Done.

+}
+
 }  // namespace content