Ignore update cursor messages from blink when the cursor position lies outside our root window

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include <set>
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
@@ skipping 80 matching lines @@
 #include "ui/wm/public/transient_window_client.h"
 #include "ui/wm/public/window_types.h"
 
 #if defined(OS_WIN)
 #include "content/browser/accessibility/browser_accessibility_manager_win.h"
 #include "content/browser/accessibility/browser_accessibility_win.h"
 #include "content/browser/renderer_host/legacy_render_widget_host_win.h"
 #include "content/common/plugin_constants_win.h"
 #include "ui/base/win/hidden_window.h"
 #include "ui/gfx/gdi_util.h"
+#include "ui/gfx/screen_win.h"
 #include "ui/gfx/win/dpi.h"
 #endif
 
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
 #include "content/common/input_messages.h"
 #include "ui/events/linux/text_edit_command_auralinux.h"
 #include "ui/events/linux/text_edit_key_bindings_delegate_auralinux.h"
 #endif
 
 using gfx::RectToSkIRect;
@@ skipping 2353 matching lines @@
 }
 
 void RenderWidgetHostViewAura::UpdateCursorIfOverSelf() {
   if (host_->GetProcess()->FastShutdownStarted())
     return;
 
   aura::Window* root_window = window_->GetRootWindow();
   if (!root_window)
     return;
 
-  gfx::Point root_window_point =
-      gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint();
+  gfx::Screen* screen = gfx::Screen::GetScreenFor(GetNativeView());
+  DCHECK(screen);
+
+  gfx::Point cursor_screen_point = screen->GetCursorScreenPoint();
+
+  // Ignore cursor update messages if the window under the cursor is not us.
+  aura::Window* window_at_screen_point = screen->GetWindowAtScreenPoint(
+      cursor_screen_point);;

[sky, 2015/11/13 16:12:18]

nit: only one ';'.

[ananta, 2015/11/13 20:09:41]

Done.

+#if defined(OS_WIN)
+  // On Windows we may fail to retrieve the aura Window at the current cursor
+  // position. This is because the WindowFromPoint API may return the legacy
+  // window which is not associated with an aura Window. In this case we need
+  // to get the aura window for the parent of the legacy window.
+  if (!window_at_screen_point) {
+    HWND hwnd_at_point = ::WindowFromPoint(cursor_screen_point.ToPOINT());
+    if (legacy_render_widget_host_HWND_ &&
+        (hwnd_at_point == legacy_render_widget_host_HWND_->hwnd())) {
+      hwnd_at_point = legacy_render_widget_host_HWND_->GetParent();
+    }
+    gfx::ScreenWin* screen_win = static_cast<gfx::ScreenWin*>(screen);

[sky, 2015/11/13 16:12:18]

What happens if running in metro mode?

[ananta, 2015/11/13 20:09:41]

In metro mode we should not be hitting the if (!window_at_screen_point)
check. I added a check for the legacy window also being present.

+    DCHECK(screen_win);
+    window_at_screen_point = screen_win->GetNativeWindowFromHWND(
+        hwnd_at_point);
+  }
+#endif
+  if (!window_at_screen_point ||
+      (window_at_screen_point->GetRootWindow() != root_window)) {
+    return;
+  }
+
+  gfx::Point root_window_point = cursor_screen_point;
   aura::client::ScreenPositionClient* screen_position_client =
       aura::client::GetScreenPositionClient(root_window);
   if (screen_position_client) {
     screen_position_client->ConvertPointFromScreen(
         root_window, &root_window_point);
   }
 
   if (root_window->GetEventHandlerForPoint(root_window_point) != window_)
     return;
 
@@ skipping 427 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewBase, public:
 
 // static
 void RenderWidgetHostViewBase::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content