Send the WebMouseWheelEvents unconverted if Shift is down.

WebMouseWheelEvents were converted based on Shift getting set. This should
not happen. Instead swap the X&Y before we goto generate the scroll
gesture.

BUG=646109

Review-Url: https://codereview.chromium.org/2359463002
Cr-Commit-Position: refs/heads/master@{#419966}

content/browser/renderer_host/input/mouse_wheel_event_queue.cc

@@ -99,10 +99,21 @@ void MouseWheelEventQueue::ProcessMouseWheelAck(
     scroll_update.type = WebInputEvent::GestureScrollUpdate;
     scroll_update.sourceDevice = blink::WebGestureDeviceTouchpad;
     scroll_update.resendingPluginId = -1;
-    scroll_update.data.scrollUpdate.deltaX =
-        event_sent_for_gesture_ack_->event.deltaX;
-    scroll_update.data.scrollUpdate.deltaY =
-        event_sent_for_gesture_ack_->event.deltaY;
+
+    // Swap X & Y if Shift is down and when there is no horizontal movement.
+    if ((event_sent_for_gesture_ack_->event.modifiers &
+         WebInputEvent::ShiftKey) != 0 &&
+        event_sent_for_gesture_ack_->event.deltaX == 0) {
+      scroll_update.data.scrollUpdate.deltaX =
+          event_sent_for_gesture_ack_->event.deltaY;
+      scroll_update.data.scrollUpdate.deltaY =
+          event_sent_for_gesture_ack_->event.deltaX;
+    } else {
+      scroll_update.data.scrollUpdate.deltaX =
+          event_sent_for_gesture_ack_->event.deltaX;
+      scroll_update.data.scrollUpdate.deltaY =
+          event_sent_for_gesture_ack_->event.deltaY;
+    }
     // Only OSX populates the phase and momentumPhase; so
     // |inertialPhase| will be UnknownMomentumPhase on all other platforms.
     if (event_sent_for_gesture_ack_->event.momentumPhase !=

ui/events/blink/web_input_event.cc

@@ -136,19 +136,10 @@ blink::WebMouseWheelEvent MakeWebMouseWheelEventFromUiEvent(
   webkit_event.timeStampSeconds = EventTimeStampToSeconds(event.time_stamp());
   webkit_event.hasPreciseScrollingDeltas = true;
 
-  float offset_ordinal_x = 0.f;
-  float offset_ordinal_y = 0.f;
-  if ((event.flags() & EF_SHIFT_DOWN) != 0 && event.x_offset() == 0) {
-    webkit_event.deltaX = event.y_offset();
-    webkit_event.deltaY = 0;
-    offset_ordinal_x = event.y_offset_ordinal();
-    offset_ordinal_y = event.x_offset_ordinal();
-  } else {
-    webkit_event.deltaX = event.x_offset();
-    webkit_event.deltaY = event.y_offset();
-    offset_ordinal_x = event.x_offset_ordinal();
-    offset_ordinal_y = event.y_offset_ordinal();
-  }
+  float offset_ordinal_x = event.x_offset_ordinal();
+  float offset_ordinal_y = event.y_offset_ordinal();
+  webkit_event.deltaX = event.x_offset();
+  webkit_event.deltaY = event.y_offset();
 
   if (offset_ordinal_x != 0.f && webkit_event.deltaX != 0.f)
     webkit_event.accelerationRatioX = offset_ordinal_x / webkit_event.deltaX;
@@ -437,13 +428,8 @@ blink::WebMouseWheelEvent MakeWebMouseWheelEventFromUiEvent(
   webkit_event.modifiers = EventFlagsToWebEventModifiers(event.flags());
   webkit_event.timeStampSeconds = EventTimeStampToSeconds(event.time_stamp());
 
-  if ((event.flags() & EF_SHIFT_DOWN) != 0 && event.x_offset() == 0) {
-    webkit_event.deltaX = event.y_offset();
-    webkit_event.deltaY = 0;
-  } else {
-    webkit_event.deltaX = event.x_offset();
-    webkit_event.deltaY = event.y_offset();
-  }
+  webkit_event.deltaX = event.x_offset();
+  webkit_event.deltaY = event.y_offset();
 
   webkit_event.wheelTicksX = webkit_event.deltaX / MouseWheelEvent::kWheelDelta;
   webkit_event.wheelTicksY = webkit_event.deltaY / MouseWheelEvent::kWheelDelta;

ui/events/blink/web_input_event_builders_win.cc

@@ -303,8 +303,6 @@ WebMouseWheelEvent WebMouseWheelEventBuilder::Build(
       wheel_delta = -wheel_delta;  // Windows is <- -/+ ->, WebKit <- +/- ->.
     }
   }
-  if (key_state & MK_SHIFT)
-    horizontal_scroll = true;
 
   // Set modifiers based on key state.
   result.modifiers =

ui/events/blink/web_input_event_unittest.cc

@@ -501,34 +501,6 @@ TEST(WebInputEventTest, TestMakeWebMouseWheelEvent) {
     EXPECT_EQ(321, webkit_event.y);
     EXPECT_EQ(321, webkit_event.windowY);
   }
-  {
-    // Mouse wheel with shift and no x offset.
-    base::TimeTicks timestamp = EventTimeForNow();
-    MouseWheelEvent ui_event(
-        gfx::Vector2d(0, -MouseWheelEvent::kWheelDelta * 2),
-        gfx::Point(123, 321), gfx::Point(123, 321), timestamp, EF_SHIFT_DOWN,
-        0);
-    blink::WebMouseWheelEvent webkit_event = MakeWebMouseWheelEvent(
-        ui_event, base::Bind(&GetScreenLocationFromEvent));
-    EXPECT_EQ(EventFlagsToWebEventModifiers(ui_event.flags()),
-              webkit_event.modifiers);
-    EXPECT_FLOAT_EQ(EventTimeStampToSeconds(timestamp),
-                    webkit_event.timeStampSeconds);
-    EXPECT_EQ(blink::WebMouseEvent::Button::NoButton, webkit_event.button);
-    EXPECT_EQ(blink::WebInputEvent::MouseWheel, webkit_event.type);
-    EXPECT_FLOAT_EQ(ui_event.y_offset() / MouseWheelEvent::kWheelDelta,
-                    webkit_event.wheelTicksX);
-    EXPECT_FLOAT_EQ(0, webkit_event.wheelTicksY);
-    EXPECT_EQ(blink::WebPointerProperties::PointerType::Mouse,
-              webkit_event.pointerType);
-    EXPECT_EQ(0, webkit_event.tiltX);
-    EXPECT_EQ(0, webkit_event.tiltY);
-    EXPECT_TRUE(std::isnan(webkit_event.force));
-    EXPECT_EQ(123, webkit_event.x);
-    EXPECT_EQ(123, webkit_event.windowX);
-    EXPECT_EQ(321, webkit_event.y);
-    EXPECT_EQ(321, webkit_event.windowY);
-  }
 }
 
 TEST(WebInputEventTest, KeyEvent) {