Do not show the mouse cursor when the display is rotated in TouchView

BUG=462883
TEST=Manual, see bug

Review URL: https://codereview.chromium.org/971753008

Cr-Commit-Position: refs/heads/master@{#322010}

ash/display/display_controller.cc

@@ -586,25 +586,34 @@ void DisplayController::UpdateMouseLocationAfterDisplayChange() {
 #if defined(USE_OZONE)
   gfx::Point target_location_in_screen = target_location_in_root;
   ::wm::ConvertPointToScreen(dst_root_window, &target_location_in_screen);
-  int64 target_display_id =
-      display_manager->FindDisplayContainingPoint(target_location_in_screen)
-          .id();
+  const gfx::Display& target_display =
+      display_manager->FindDisplayContainingPoint(target_location_in_screen);
+  int64 target_display_id = target_display.id();
 
   // Do not move the cursor if the cursor's location did not change. This avoids
-  // moving (and showing) the cursor on startup.
-  // - |cursor_location_in_screen_coords_for_restore_| is checked to ensure that
-  //   the cursor is moved when the cursor's native position does not change but
-  //   the scale factor or rotation of the display it is on have changed.
-  // - |cursor_display_id_for_restore_| is checked to ensure that the cursor is
-  //   moved when the cursor's native position and screen position do not change
-  //   but the display that it is on has changed. This occurs when swapping the
-  //   primary display.
+  // moving (and showing) the cursor:
+  // - At startup.
+  // - When the device is rotated in maximized mode.
+  // |cursor_display_id_for_restore_| is checked to ensure that the cursor is
+  // moved when the cursor's native position does not change but the display
+  // that it is on has changed. This occurs when swapping the primary display.
   if (target_location_in_native !=
           cursor_location_in_native_coords_for_restore_ ||
-      target_location_in_screen !=
-          cursor_location_in_screen_coords_for_restore_ ||
       target_display_id != cursor_display_id_for_restore_) {
     dst_root_window->MoveCursorTo(target_location_in_root);
+  } else if (target_location_in_screen !=
+             cursor_location_in_screen_coords_for_restore_) {
+    // The cursor's native position did not change but its screen position did
+    // change. This occurs when the scale factor or the rotation of the display
+    // that the cursor is on changes.
+    Shell::GetInstance()->cursor_manager()->SetDisplay(target_display);
+
+    // Update the cursor's root location. This ends up dispatching a synthetic
+    // mouse move. The synthetic mouse move updates the composited cursor's
+    // location and hover effects. Synthetic mouse moves do not affect the
+    // cursor's visibility.
+    dst_root_window->GetHost()->dispatcher()->OnCursorMovedToRootLocation(
+        target_location_in_root);
   }
 #else
   dst_root_window->MoveCursorTo(target_location_in_root);

ui/aura/window_event_dispatcher.cc

@@ -208,7 +208,10 @@ void WindowEventDispatcher::OnHostLostMouseGrab() {
 void WindowEventDispatcher::OnCursorMovedToRootLocation(
     const gfx::Point& root_location) {
   SetLastMouseLocation(window(), root_location);
-  synthesize_mouse_move_ = false;
+
+  // Synthesize a mouse move in case the cursor's location in root coordinates
+  // changed but its position in WindowTreeHost coordinates did not.
+  PostSynthesizeMouseMove();
 }
 
 void WindowEventDispatcher::OnPostNotifiedWindowDestroying(Window* window) {

ui/aura/window_event_dispatcher_unittest.cc

@@ -2540,4 +2540,36 @@ TEST_F(WindowEventDispatcherTest, TouchMovesMarkedWhenCausingScroll) {
 
   root_window()->RemovePreTargetHandler(&recorder);
 }
+
+// OnCursorMovedToRootLocation() is sometimes called instead of
+// WindowTreeHost::MoveCursorTo() when the cursor did not move but the
+// cursor's position in root coordinates has changed (e.g. when the displays's
+// scale factor changed). Test that hover effects are properly updated.
+TEST_F(WindowEventDispatcherTest, OnCursorMovedToRootLocationUpdatesHover) {
+  WindowEventDispatcher* dispatcher = host()->dispatcher();
+
+  scoped_ptr<Window> w(CreateNormalWindow(1, root_window(), nullptr));
+  w->SetBounds(gfx::Rect(20, 20, 20, 20));
+  w->Show();
+
+  // Move the cursor off of |w|.
+  dispatcher->OnCursorMovedToRootLocation(gfx::Point(100, 100));
+
+  EventFilterRecorder recorder;
+  w->AddPreTargetHandler(&recorder);
+  dispatcher->OnCursorMovedToRootLocation(gfx::Point(22, 22));
+  RunAllPendingInMessageLoop();
+  EXPECT_TRUE(recorder.HasReceivedEvent(ui::ET_MOUSE_ENTERED));
+  recorder.Reset();
+
+  // The cursor should not be over |w| after changing the device scale factor to
+  // 2x. A ET_MOUSE_EXITED event should have been sent to |w|.
+  test_screen()->SetDeviceScaleFactor(2.f);
+  dispatcher->OnCursorMovedToRootLocation(gfx::Point(11, 11));
+  RunAllPendingInMessageLoop();
+  EXPECT_TRUE(recorder.HasReceivedEvent(ui::ET_MOUSE_EXITED));
+
+  w->RemovePreTargetHandler(&recorder);
+}
+
 }  // namespace aura