Fix can not scroll issue in HiDPI after resize the window

The root cause of this issue is we use device pixel to check
if the event is non client event but NonClientFrameView is
using DIP coordinate. The mouse press event in resizing should
be non client event otherwise FindTargetForEvent think some
window is capturing the events then route the following events
to wrong window until next mouse press.

Bug: 881975
Change-Id: I66492c05e14add875775ae9dae32b456ab23f23d
Reviewed-on: https://chromium-review.googlesource.com/c/1333992Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Jianpeng Chao <chaopeng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610080}

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

@@ -1819,8 +1819,10 @@ void DesktopWindowTreeHostX11::DispatchMouseEvent(ui::MouseEvent* event) {
   // WindowTreeHost that hosts ash.
   if (content_window() && content_window()->delegate()) {
     int flags = event->flags();
+    gfx::Point location_in_dip = event->location();
+    GetRootTransform().TransformPointReverse(&location_in_dip);
     int hit_test_code =
-        content_window()->delegate()->GetNonClientComponent(event->location());
+        content_window()->delegate()->GetNonClientComponent(location_in_dip);
     if (hit_test_code != HTCLIENT && hit_test_code != HTNOWHERE)
       flags |= ui::EF_IS_NON_CLIENT;
     event->set_flags(flags);

ui/views/widget/desktop_aura/desktop_window_tree_host_x11_unittest.cc

@@ -79,7 +79,12 @@ class ShapedNonClientFrameView : public NonClientFrameView {
       const gfx::Rect& client_bounds) const override {
     return client_bounds;
   }
-  int NonClientHitTest(const gfx::Point& point) override { return HTNOWHERE; }
+  int NonClientHitTest(const gfx::Point& point) override {
+    // Fake bottom for non client event test.
+    if (point == gfx::Point(500, 500))
+      return HTBOTTOM;
+    return HTNOWHERE;
+  }
   void GetWindowMask(const gfx::Size& size, gfx::Path* window_mask) override {
     int right = size.width();
     int bottom = size.height();
@@ -168,11 +173,15 @@ void RunAllPendingInMessageLoop() {
 
 class DesktopWindowTreeHostX11Test : public ViewsTestBase {
  public:
-  DesktopWindowTreeHostX11Test() {
-  }
+  DesktopWindowTreeHostX11Test()
+      : event_source_(ui::PlatformEventSource::GetInstance()) {}
   ~DesktopWindowTreeHostX11Test() override {}
 
   void SetUp() override {
+    std::vector<int> pointer_devices;
+    pointer_devices.push_back(kPointerDeviceId);
+    ui::TouchFactory::GetInstance()->SetPointerDeviceForTest(pointer_devices);
+
     ViewsTestBase::SetUp();
 
     // Make X11 synchronous for our display connection. This does not force the
@@ -185,7 +194,17 @@ class DesktopWindowTreeHostX11Test : public ViewsTestBase {
     ViewsTestBase::TearDown();
   }
 
+  void DispatchSingleEventToWidget(XEvent* event, Widget* widget) {
+    DCHECK_EQ(GenericEvent, event->type);
+    XIDeviceEvent* device_event =
+        static_cast<XIDeviceEvent*>(event->xcookie.data);
+    device_event->event =
+        widget->GetNativeWindow()->GetHost()->GetAcceleratedWidget();
+    event_source_.Dispatch(event);
+  }
+
  private:
+  ui::test::PlatformEventSourceTestAPI event_source_;
   DISALLOW_COPY_AND_ASSIGN(DesktopWindowTreeHostX11Test);
 };
 
@@ -501,19 +520,9 @@ class MouseEventRecorder : public ui::EventHandler {
 class DesktopWindowTreeHostX11HighDPITest
     : public DesktopWindowTreeHostX11Test {
  public:
-  DesktopWindowTreeHostX11HighDPITest()
-      : event_source_(ui::PlatformEventSource::GetInstance()) {}
+  DesktopWindowTreeHostX11HighDPITest() {}
   ~DesktopWindowTreeHostX11HighDPITest() override {}
 
-  void DispatchSingleEventToWidget(XEvent* event, Widget* widget) {
-    DCHECK_EQ(GenericEvent, event->type);
-    XIDeviceEvent* device_event =
-        static_cast<XIDeviceEvent*>(event->xcookie.data);
-    device_event->event =
-        widget->GetNativeWindow()->GetHost()->GetAcceleratedWidget();
-    event_source_.Dispatch(event);
-  }
-
   void PretendCapture(views::Widget* capture_widget) {
     DesktopWindowTreeHostX11* capture_host = nullptr;
     if (capture_widget) {
@@ -529,14 +538,10 @@ class DesktopWindowTreeHostX11HighDPITest
   void SetUp() override {
     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
     command_line->AppendSwitchASCII(switches::kForceDeviceScaleFactor, "2");
-    std::vector<int> pointer_devices;
-    pointer_devices.push_back(kPointerDeviceId);
-    ui::TouchFactory::GetInstance()->SetPointerDeviceForTest(pointer_devices);
 
     DesktopWindowTreeHostX11Test::SetUp();
   }
 
-  ui::test::PlatformEventSourceTestAPI event_source_;
   DISALLOW_COPY_AND_ASSIGN(DesktopWindowTreeHostX11HighDPITest);
 };
 
@@ -597,4 +602,52 @@ TEST_F(DesktopWindowTreeHostX11HighDPITest,
   second.GetNativeWindow()->RemovePreTargetHandler(&second_recorder);
 }
 
+TEST_F(DesktopWindowTreeHostX11Test, MouseNCEvents) {
+  std::unique_ptr<Widget> widget = CreateWidget(new ShapedWidgetDelegate());
+  widget->Show();
+
+  ui::X11EventSource::GetInstance()->DispatchXEvents();
+
+  widget->SetBounds(gfx::Rect(100, 100, 501, 501));
+  ui::X11EventSource::GetInstance()->DispatchXEvents();
+
+  MouseEventRecorder recorder;
+  widget->GetNativeWindow()->AddPreTargetHandler(&recorder);
+
+  ui::ScopedXI2Event event;
+  event.InitGenericButtonEvent(kPointerDeviceId, ui::ET_MOUSE_PRESSED,
+                               gfx::Point(500, 500), ui::EF_LEFT_MOUSE_BUTTON);
+
+  DispatchSingleEventToWidget(event, widget.get());
+  ASSERT_EQ(1u, recorder.mouse_events().size());
+  EXPECT_EQ(ui::ET_MOUSE_PRESSED, recorder.mouse_events()[0].type());
+  EXPECT_TRUE(recorder.mouse_events()[0].flags() & ui::EF_IS_NON_CLIENT);
+
+  widget->GetNativeWindow()->RemovePreTargetHandler(&recorder);
+}
+
+TEST_F(DesktopWindowTreeHostX11HighDPITest, MouseNCEvents) {
+  std::unique_ptr<Widget> widget = CreateWidget(new ShapedWidgetDelegate());
+  widget->Show();
+
+  ui::X11EventSource::GetInstance()->DispatchXEvents();
+
+  widget->SetBounds(gfx::Rect(100, 100, 1000, 1000));
+  ui::X11EventSource::GetInstance()->DispatchXEvents();
+
+  MouseEventRecorder recorder;
+  widget->GetNativeWindow()->AddPreTargetHandler(&recorder);
+
+  ui::ScopedXI2Event event;
+  event.InitGenericButtonEvent(kPointerDeviceId, ui::ET_MOUSE_PRESSED,
+                               gfx::Point(1001, 1001),
+                               ui::EF_LEFT_MOUSE_BUTTON);
+  DispatchSingleEventToWidget(event, widget.get());
+  ASSERT_EQ(1u, recorder.mouse_events().size());
+  EXPECT_EQ(ui::ET_MOUSE_PRESSED, recorder.mouse_events()[0].type());
+  EXPECT_TRUE(recorder.mouse_events()[0].flags() & ui::EF_IS_NON_CLIENT);
+
+  widget->GetNativeWindow()->RemovePreTargetHandler(&recorder);
+}
+
 }  // namespace views