mus: Use TooltipManagerAura in NativeWidgetMus.

ui/views/mus/window_manager_connection.cc

 // Copyright 2015 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/views/mus/window_manager_connection.h"
 
+#include <algorithm>
 #include <set>
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_local.h"
 #include "services/shell/public/cpp/connection.h"
 #include "services/shell/public/cpp/connector.h"
 #include "services/ui/public/cpp/gpu_service.h"
 #include "services/ui/public/cpp/property_type_converters.h"
@@ skipping 15 matching lines @@
 namespace views {
 namespace {
 
 using WindowManagerConnectionPtr =
     base::ThreadLocalPointer<views::WindowManagerConnection>;
 
 // Env is thread local so that aura may be used on multiple threads.
 base::LazyInstance<WindowManagerConnectionPtr>::Leaky lazy_tls_ptr =
     LAZY_INSTANCE_INITIALIZER;
 
+ui::Window* GetWindowFrom(const std::vector<display::Display>& displays,
+                          const std::vector<ui::Window*>& windows,
+                          const gfx::Point& screen_point) {
+  for (ui::Window* window : windows) {
+    const int64_t window_display_id = window->GetRoot()->display_id();

[sky, 2016/10/06 21:23:42]

Each window has a display id, so you should be able to use window->display_id()
here.

+    for (display::Display display : displays) {

[sky, 2016/10/06 21:23:42]

As you're going to be doing this in a loop every time I think it's worth
building a map display_id to display that you pass to this function.

+      if (display.id() != window_display_id)
+        continue;
+
+      gfx::Point display_origin = display.bounds().origin();
+      gfx::Rect bounds_in_screen = window->GetBoundsInRoot();
+      bounds_in_screen.Offset(display_origin.x(), display_origin.y());
+
+      if (bounds_in_screen.Contains(screen_point)) {
+        if (!window->children().empty()) {
+          ui::Window* child =
+              GetWindowFrom(displays, window->children(), screen_point);
+          if (child)
+            return child;
+        }
+
+        return window;
+      }
+    }
+  }
+  return nullptr;
+}
+
 }  // namespace
 
 WindowManagerConnection::~WindowManagerConnection() {
   // ~WindowTreeClient calls back to us (we're its delegate), destroy it while
   // we are still valid.
   client_.reset();
   ui::OSExchangeDataProviderFactory::SetFactory(nullptr);
   ui::Clipboard::DestroyClipboardForCurrentThread();
   gpu_service_.reset();
   lazy_tls_ptr.Pointer()->Set(nullptr);
@@ skipping 108 matching lines @@
 
 void WindowManagerConnection::OnWindowManagerFrameValuesChanged() {
   if (client_)
     NativeWidgetMus::NotifyFrameChanged(client_.get());
 }
 
 gfx::Point WindowManagerConnection::GetCursorScreenPoint() {
   return client_->GetCursorScreenPoint();
 }
 
+ui::Window* WindowManagerConnection::GetWindowAtScreenPoint(

[sky, 2016/10/06 21:23:42]

Please add test coverage of this.

+    const gfx::Point& point) {
+  std::vector<display::Display> displays =
+      display::Screen::GetScreen()->GetAllDisplays();
+
+  const std::set<ui::Window*>& roots = GetRoots();
+  std::vector<ui::Window*> windows;
+  std::copy(roots.begin(), roots.end(), std::back_inserter(windows));
+  return GetWindowFrom(displays, windows, point);
+}
+
 std::unique_ptr<OSExchangeData::Provider>
 WindowManagerConnection::BuildProvider() {
   return base::MakeUnique<OSExchangeDataProviderMus>();
 }
 
 }  // namespace views