Avoid two targeting phases in aura client-lib and EventProcessor.

1. Client-lib now skips the step where it converted the event location from
target window's coordinate system to root window's coordinate system; and
sets the target window received from mus-ws to be the target for that event.

2. Added two virtual functions in EventProcessor responsible for getting the
window with the right targeter (either root window or the farthest ancestor
with a targeter set) and for getting the default targeter (WindowTargeter)
respectively.

3. WindowEventDispatcher now is responsible for finding the right target and
doing the conversion between their coordinate systems.

4. WindowTreeHost only sets a targeter for the root window in non-mus mode
so that we don't end up walking all the way up to the root window just to use
the default event targeter.

This also solves the bug where we were using DIP for conversion in the
client-lib but event location was still in pixels at that time.

BUG=687700
TEST=aura_unittests
     manual (--force-device-scale-factor=2)

Review-Url: https://codereview.chromium.org/2681613002
Cr-Commit-Position: refs/heads/master@{#452393}

ash/root_window_controller.cc

@@ -486,8 +486,9 @@ WmWindow* RootWindowController::FindEventTarget(
                             location_in_root, ui::EventTimeForNow(),
                             ui::EF_NONE, ui::EF_NONE);
   ui::EventTarget* event_handler =
-      static_cast<ui::EventTarget*>(root_window)
-          ->GetEventTargeter()
+      root_window->GetHost()
+          ->dispatcher()
+          ->GetDefaultEventTargeter()
           ->FindTargetForEvent(root_window, &test_event);
   return WmWindow::Get(static_cast<aura::Window*>(event_handler));
 }

ash/shelf/shelf_widget_unittest.cc

@@ -214,8 +214,9 @@ TEST_F(ShelfWidgetTest, ShelfEdgeOverlappingWindowHitTestMouse) {
   gfx::Rect widget_bounds = widget->GetWindowBoundsInScreen();
   EXPECT_TRUE(widget_bounds.Intersects(shelf_bounds));
 
-  ui::EventTarget* root = widget->GetNativeWindow()->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = widget->GetNativeWindow()->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
   {
     // Create a mouse-event targeting the top of the shelf widget. The
     // window-targeter should find |widget| as the target (instead of the
@@ -290,8 +291,9 @@ TEST_F(ShelfWidgetTest, HiddenShelfHitTestTouch) {
   widget->Init(params);
   widget->Show();
 
-  ui::EventTarget* root = shelf_widget->GetNativeWindow()->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = shelf_widget->GetNativeWindow()->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
   // Touch just over the shelf. Since the shelf is visible, the window-targeter
   // should not find the shelf as the target.
   {

ash/wm/immersive_fullscreen_controller_unittest.cc

@@ -736,8 +736,9 @@ TEST_F(ImmersiveFullscreenControllerTest, EventsDoNotLeakToWindowUnderneath) {
 
   ui::TouchEvent touch(ui::ET_TOUCH_MOVED, gfx::Point(10, top), 0,
                        ui::EventTimeForNow());
-  ui::EventTarget* root = window()->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = window()->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
   EXPECT_EQ(window(), targeter->FindTargetForEvent(root, &touch));
 
   SetEnabled(true);

ash/wm/overview/window_selector_unittest.cc

@@ -1026,7 +1026,8 @@ TEST_F(WindowSelectorTest, WindowDoesNotReceiveEvents) {
                         ui::EventTimeForNow(), ui::EF_NONE, ui::EF_NONE);
 
   ui::EventTarget* root_target = root_window;
-  ui::EventTargeter* targeter = root_target->GetEventTargeter();
+  ui::EventTargeter* targeter =
+      root_window->GetHost()->dispatcher()->GetDefaultEventTargeter();
 
   // The event should target the window because we are still not in overview
   // mode.

ash/wm/panels/panel_layout_manager_unittest.cc

@@ -839,8 +839,9 @@ TEST_F(PanelLayoutManagerTest, TouchHitTestPanel) {
   aura::test::TestWindowDelegate delegate;
   std::unique_ptr<aura::Window> w(
       CreatePanelWindowWithDelegate(&delegate, gfx::Rect(0, 0, 200, 200)));
-  ui::EventTarget* root = w->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = w->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
 
   // Note that the constants used in the touch locations below are
   // arbitrarily-selected small numbers which will ensure the point is

ash/wm/workspace_controller_unittest.cc

@@ -1481,8 +1481,9 @@ TEST_F(WorkspaceControllerTest, WindowEdgeHitTest) {
   ParentWindowInPrimaryRootWindow(second.get());
   second->Show();
 
-  ui::EventTarget* root = first->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = first->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
 
   // The windows overlap, and |second| is on top of |first|. Events targeted
   // slightly outside the edges of the |second| window should still be targeted
@@ -1530,8 +1531,9 @@ TEST_F(WorkspaceControllerTest, WindowEdgeMouseHitTestPanel) {
   aura::test::TestWindowDelegate delegate;
   std::unique_ptr<Window> window(
       CreateTestPanel(&delegate, gfx::Rect(20, 10, 100, 50)));
-  ui::EventTarget* root = window->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = window->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
   const gfx::Rect bounds = window->bounds();
   const int kNumPoints = 5;
   struct {
@@ -1566,8 +1568,9 @@ TEST_F(WorkspaceControllerTest, WindowEdgeTouchHitTestPanel) {
   aura::test::TestWindowDelegate delegate;
   std::unique_ptr<Window> window(
       CreateTestPanel(&delegate, gfx::Rect(20, 10, 100, 50)));
-  ui::EventTarget* root = window->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = window->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
   const gfx::Rect bounds = window->bounds();
   const int kNumPoints = 5;
   struct {
@@ -1607,8 +1610,9 @@ TEST_F(WorkspaceControllerTest, WindowEdgeHitTestDocked) {
       window->GetRootWindow(), kShellWindowId_DockedContainer);
   docked_container->AddChild(window.get());
   window->Show();
-  ui::EventTarget* root = window->GetRootWindow();
-  ui::EventTargeter* targeter = root->GetEventTargeter();
+  aura::Window* root = window->GetRootWindow();
+  ui::EventTargeter* targeter =
+      root->GetHost()->dispatcher()->GetDefaultEventTargeter();
   const gfx::Rect bounds = window->bounds();
   const int kNumPoints = 5;
   struct {

ui/aura/BUILD.gn

@@ -252,6 +252,8 @@ static_library("test_support") {
     "test/test_window_delegate.h",
     "test/test_window_parenting_client.cc",
     "test/test_window_parenting_client.h",
+    "test/test_window_targeter.cc",
+    "test/test_window_targeter.h",
     "test/test_windows.cc",
     "test/test_windows.h",
     "test/ui_controls_factory_aura.h",

ui/aura/mus/window_tree_client.cc

@@ -160,6 +160,14 @@ void ConvertEventLocationToDip(int64_t display_id, ui::LocatedEvent* event) {
   event->set_root_location(root_location);
 }
 
+// Set the |target| to be the target window of this |event| and send it to
+// the EventProcessor.
+void DispatchEventToTarget(ui::Event* event, WindowMus* target) {
+  ui::Event::DispatcherApi dispatch_helper(event);
+  dispatch_helper.set_target(target->GetWindow());
+  GetWindowTreeHostMus(target)->SendEventToProcessor(event);
+}
+
 }  // namespace
 
 WindowTreeClient::WindowTreeClient(
@@ -1150,34 +1158,22 @@ void WindowTreeClient::OnWindowInputEvent(uint32_t event_id,
     return;
   }
 
-  WindowTreeHostMus* host = GetWindowTreeHostMus(window);
-  DCHECK(host);
-
-  // The location of the event is relative to |window|. As the event is handed
-  // to WindowTreeHost we need it to be relative to WindowTreeHost.
-  if (event->IsLocatedEvent()) {
-    gfx::Point host_location = event->AsLocatedEvent()->location();
-    aura::Window::ConvertPointToTarget(window->GetWindow(), host->window(),
-                                       &host_location);
-    event->AsLocatedEvent()->set_location(host_location);
-  }
-
   EventAckHandler ack_handler(CreateEventResultCallback(event_id));
   // TODO(moshayedi): crbug.com/617222. No need to convert to ui::MouseEvent or
   // ui::TouchEvent once we have proper support for pointer events.
   if (event->IsMousePointerEvent()) {
     if (event->type() == ui::ET_POINTER_WHEEL_CHANGED) {
       ui::MouseWheelEvent mapped_event(*event->AsPointerEvent());
-      host->SendEventToProcessor(&mapped_event);
+      DispatchEventToTarget(&mapped_event, window);
     } else {
       ui::MouseEvent mapped_event(*event->AsPointerEvent());
-      host->SendEventToProcessor(&mapped_event);
+      DispatchEventToTarget(&mapped_event, window);
     }
   } else if (event->IsTouchPointerEvent()) {
     ui::TouchEvent mapped_event(*event->AsPointerEvent());
-    host->SendEventToProcessor(&mapped_event);
+    DispatchEventToTarget(&mapped_event, window);
   } else {
-    host->SendEventToProcessor(event.get());
+    DispatchEventToTarget(event.get(), window);
   }
   ack_handler.set_handled(event->handled());
 }