views/mus: Destroy DeviceDataManager only if WindowManagerConnection owns it.

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 <utility>
 
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
@@ skipping 84 matching lines @@
     // Last PointerWatcher removed, stop the event observer.
     client_->SetEventObserver(nullptr);
   }
 }
 
 WindowManagerConnection::WindowManagerConnection(
     shell::Connector* connector,
     const shell::Identity& identity)
     : connector_(connector),
       identity_(identity),
-      client_(nullptr) {
+      created_device_data_manager_(false) {
   client_.reset(new mus::WindowTreeClient(this, nullptr, nullptr));
   client_->ConnectViaWindowTreeFactory(connector_);
 
   screen_.reset(new ScreenMus(this));
   screen_->Init(connector);
 
-  // TODO(sad): We should have a DeviceDataManager implementation that talks to
-  // a mojo service to learn about the input-devices on the system.
-  // http://crbug.com/601981
-  ui::DeviceDataManager::CreateInstance();
+  if (!ui::DeviceDataManager::HasInstance()) {
+    // TODO(sad): We should have a DeviceDataManager implementation that talks
+    // to a mojo service to learn about the input-devices on the system.
+    // http://crbug.com/601981
+    ui::DeviceDataManager::CreateInstance();
+    created_device_data_manager_ = true;
+  }
 
   ViewsDelegate::GetInstance()->set_native_widget_factory(base::Bind(
       &WindowManagerConnection::CreateNativeWidgetMus,
       base::Unretained(this),
       std::map<std::string, std::vector<uint8_t>>()));
 }
 
 WindowManagerConnection::~WindowManagerConnection() {
   // ~WindowTreeClient calls back to us (we're its delegate), destroy it while
   // we are still valid.
   client_.reset();
-
-  ui::DeviceDataManager::DeleteInstance();
+  if (created_device_data_manager_)
+    ui::DeviceDataManager::DeleteInstance();
 }
 
 bool WindowManagerConnection::HasPointerWatcher() {
   // Check to see if we really have any observers left. This doesn't use
   // base::ObserverList<>::might_have_observers() because that returns true
   // during iteration over the list even when the last observer is removed.
   base::ObserverList<PointerWatcher>::Iterator iterator(&pointer_watchers_);
   return !!iterator.GetNext();
 }
 
@@ skipping 30 matching lines @@
 void WindowManagerConnection::OnWindowManagerFrameValuesChanged() {
   if (client_)
     NativeWidgetMus::NotifyFrameChanged(client_.get());
 }
 
 gfx::Point WindowManagerConnection::GetCursorScreenPoint() {
   return client_->GetCursorScreenPoint();
 }
 
 }  // namespace views