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 2453 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::Point cursor_screen_point =
       gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint();
+
+  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;
 
+#if defined(OS_WIN)
+  // We can receive SetCursor messages from blink even when we are not the
+  // foreground window. This can happen for e.g. when the dev tools window
+  // is updating styles etc. We only want the cursor update to occur on
+  // the portion of the window outside the foreground window.
+  if (legacy_render_widget_host_HWND_) {

[scottmg, 2015/11/11 05:37:52]

Couldn't this happen when the legacy hwnd is disabled too?

[ananta, 2015/11/11 19:35:08]

The legacy window is disabled only for metro mode and by a command line switch.
We are using the legacy window as a signal that this is not metro mode.

+    HWND focus_window = ::GetFocus();
+    if (focus_window != GetNativeView()->GetHost()->GetAcceleratedWidget()) {
+      RECT focus_window_screen_rect = {0};
+      ::GetWindowRect(focus_window, &focus_window_screen_rect);
+      // The cursor is within the bounds of another window. Ignore.
+      if (::PtInRect(&focus_window_screen_rect, cursor_screen_point.ToPOINT()))
+        return;
+    }
+  }
+#endif
+
   gfx::NativeCursor cursor = current_cursor_.GetNativeCursor();
   // Do not show loading cursor when the cursor is currently hidden.
   if (is_loading_ && cursor != ui::kCursorNone)
     cursor = ui::kCursorPointer;
 
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(root_window);
   if (cursor_client) {
     cursor_client->SetCursor(cursor);
   }
@@ skipping 417 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewBase, public:
 
 // static
 void RenderWidgetHostViewBase::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content