[UseZoomForDSF] Alwatys use DIP coordinates in pepper plugin

ui/events/blink/blink_event_util_unittest.cc

+// Copyright 2016 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 "ui/events/blink/blink_event_util.h"
+
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+#include "ui/events/gesture_event_details.h"
+
+namespace ui {
+
+using BlinkEventUtilTest = testing::Test;
+
+TEST(BlinkEventUtilTest, NoScalingWith1DSF) {
+  const ui::GestureEventDetails details(ui::ET_GESTURE_SCROLL_UPDATE,
+                                        1,
+                                        1);
+  auto event =
+      CreateWebGestureEvent(details,
+                            base::TimeDelta::FromMilliseconds(1),
+                            gfx::PointF(1.f, 1.f),
+                            gfx::PointF(1.f, 1.f),
+                            0);
+  EXPECT_FALSE(ScaleWebInputEvent(event, 1.f));
+  EXPECT_TRUE(ScaleWebInputEvent(event, 2.f));
+}
+
+}  // namespace ui