Change OnWindowInputEvent to use display_id to find the host and update event root_location in WS.

services/ui/ws/window_manager_state.cc

 // Copyright 2016 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 "services/ui/ws/window_manager_state.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "services/service_manager/public/interfaces/connector.mojom.h"
 #include "services/ui/common/accelerator_util.h"
 #include "services/ui/ws/accelerator.h"
 #include "services/ui/ws/cursor_location_manager.h"
 #include "services/ui/ws/display.h"
 #include "services/ui/ws/display_manager.h"
 #include "services/ui/ws/platform_display.h"
 #include "services/ui/ws/server_window.h"
 #include "services/ui/ws/user_display_manager.h"
 #include "services/ui/ws/user_id_tracker.h"
+#include "services/ui/ws/window_coordinate_conversions.h"
 #include "services/ui/ws/window_manager_display_root.h"
 #include "services/ui/ws/window_server.h"
 #include "services/ui/ws/window_tree.h"
 #include "ui/events/event.h"
 
 namespace ui {
 namespace ws {
 namespace {
 
 // Flags that matter when checking if a key event matches an accelerator.
@@ skipping 543 matching lines @@
       ->display_manager()
       ->GetCursorLocationManager(user_id())
       ->OnMouseCursorLocationChanged(point);
 }
 
 void WindowManagerState::DispatchInputEventToWindow(ServerWindow* target,
                                                     ClientSpecificId client_id,
                                                     const ui::Event& event,
                                                     Accelerator* accelerator) {
   DCHECK(IsActive());
+
+  std::unique_ptr<ui::Event> clone = ui::Event::Clone(event);
+  // Convert the root_location of this |event| to be from the coordinate system
+  // of the root window of the |window_tree_| to the coordinate system of the
+  // root_window of the window tree associated with this |client_id|.
+  if (client_id != window_tree_->id() && event.IsLocatedEvent()) {
+    WindowTree* target_tree = window_server()->GetTreeWithId(client_id);
+    CHECK_LE(1u, window_tree_->roots().size());
+    CHECK_LE(1u, target_tree->roots().size());

[sadrul, 2017/03/14 16:08:32]

DCHECK_GE

[riajiang, 2017/03/14 19:03:26]

Done.

+    const ServerWindow* window_tree_root = *window_tree_->roots().begin();
+    const ServerWindow* target_window_tree_root = *target_tree->roots().begin();

[sadrul, 2017/03/14 16:08:32]

I don't think these will always give you the right results. You should do
something more like:

  const ServerWindow* wm_root = window_tree_->FindRootFor(target);
  const ServerWindow* target_root = target_tree->FindRootFor(target);
  DCHECK(wm_root);
  DCHECK(target_root);
  DCHECK(wm_root->Contains(target_root));

Where:

const ServerWindow* WindowTree:FindRootFor(const ServerWindow* window) {
  for (const ServerWindow* parent = window;
             parent; parent = parent->parent()) {
    if (roots_.find(parent))
      return parent;
  }
  return nullptr;
}

This ensures that you are using the right root from each tree.

[riajiang, 2017/03/14 19:03:26]

Done.

+    gfx::Point new_root_location =
+        ConvertPointBetweenWindows(window_tree_root, target_window_tree_root,
+                                   event.AsLocatedEvent()->root_location());
+    clone->AsLocatedEvent()->set_root_location(new_root_location);
+  }
+
   // TODO(sky): this needs to see if another wms has capture and if so forward
   // to it.
   if (in_flight_event_details_) {
     std::unique_ptr<ProcessedEventTarget> processed_event_target(
         new ProcessedEventTarget(target, client_id, accelerator));
-    QueueEvent(event, std::move(processed_event_target),
+    QueueEvent(*clone, std::move(processed_event_target),
                event_processing_display_id_);
     return;
   }
 
   base::WeakPtr<Accelerator> weak_accelerator;
   if (accelerator)
     weak_accelerator = accelerator->GetWeakPtr();
-  DispatchInputEventToWindowImpl(target, client_id, event, weak_accelerator);
+  DispatchInputEventToWindowImpl(target, client_id, *clone, weak_accelerator);
 }
 
 ClientSpecificId WindowManagerState::GetEventTargetClientId(
     const ServerWindow* window,
     bool in_nonclient_area) {
   if (in_nonclient_area) {
     // Events in the non-client area always go to the window manager.
     return window_tree_->id();
   }
 
@@ skipping 61 matching lines @@
       window->RemoveObserver(this);
       orphaned_window_manager_display_roots_.erase(iter);
       return;
     }
   }
   NOTREACHED();
 }
 
 }  // namespace ws
 }  // namespace ui