Add support to the UI Service to run it inside the browser's process.

services/ui/ws/threaded_image_cursors.cc

Index: services/ui/ws/threaded_image_cursors.cc
diff --git a/services/ui/ws/threaded_image_cursors.cc b/services/ui/ws/threaded_image_cursors.cc
new file mode 100644
index 0000000000000000000000000000000000000000..eb7f2daf2d950d8f9e34e509839c5bbad49b2bc4
--- /dev/null
+++ b/services/ui/ws/threaded_image_cursors.cc
@@ -0,0 +1,134 @@
+// Copyright 2017 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/threaded_image_cursors.h"
+
+#include "base/bind.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "services/ui/common/image_cursors_set.h"
+#include "ui/base/cursor/image_cursors.h"
+#include "ui/platform_window/platform_window.h"
+
+namespace ui {
+namespace ws {
+namespace {
+
+void AddImageCursorsOnResourceThread(
+    base::WeakPtr<ui::ImageCursorsSet> image_cursors_set_weak_ptr,
+    std::unique_ptr<ui::ImageCursors> image_cursors) {
+  if (image_cursors_set_weak_ptr)
+    image_cursors_set_weak_ptr->AddImageCursors(std::move(image_cursors));
+}
+
+void RemoveImageCursorsOnResourceThread(
+    base::WeakPtr<ui::ImageCursorsSet> image_cursors_set_weak_ptr,
+    base::WeakPtr<ui::ImageCursors> image_cursors_weak_ptr) {
+  if (image_cursors_set_weak_ptr && image_cursors_weak_ptr) {
+    image_cursors_set_weak_ptr->DeleteImageCursors(
+        image_cursors_weak_ptr.get());
+  }
+}
+
+void SetDisplayOnResourceThread(
+    base::WeakPtr<ui::ImageCursors> image_cursors_weak_ptr,
+    const display::Display& display,
+    float scale_factor) {
+  if (image_cursors_weak_ptr)
+    image_cursors_weak_ptr->SetDisplay(display, scale_factor);
+}
+
+void SetCursorSizeOnResourceThread(
+    base::WeakPtr<ui::ImageCursors> image_cursors_weak_ptr,
+    CursorSize cursor_size) {
+  if (image_cursors_weak_ptr)
+    image_cursors_weak_ptr->SetCursorSize(cursor_size);
+}
+
+// Executed on |resource_task_runner_|. Sets cursor type on
+// |image_cursors_set_weak_ptr_|, and then schedules a task on
+// |ui_service_task_runner_| to set the corresponding PlatformCursor on the
+// provided |platform_window|.
+// |platform_window| pointer needs to be valid while
+// |threaded_image_cursors_weak_ptr| is not invalidated.
+void SetCursorOnResourceThread(
+    base::WeakPtr<ui::ImageCursors> image_cursors_weak_ptr,
+    ui::CursorType cursor_type,
+    ui::PlatformWindow* platform_window,
+    scoped_refptr<base::SingleThreadTaskRunner> ui_service_task_runner_,
+    base::WeakPtr<ThreadedImageCursors> threaded_image_cursors_weak_ptr) {
+  if (image_cursors_weak_ptr) {
+    ui::Cursor native_cursor(cursor_type);
+    image_cursors_weak_ptr->SetPlatformCursor(&native_cursor);
+    // |platform_window| is owned by the UI Service thread, so setting the
+    // cursor on it also needs to happen on that thread.
+    ui_service_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&ThreadedImageCursors::SetCursorOnPlatformWindow,
+                              threaded_image_cursors_weak_ptr,
+                              native_cursor.platform(), platform_window));
+  }
+}
+
+}  // namespace
+
+ThreadedImageCursors::ThreadedImageCursors(
+    scoped_refptr<base::SingleThreadTaskRunner>& resource_task_runner,
+    base::WeakPtr<ui::ImageCursorsSet> image_cursors_set_weak_ptr)
+    : resource_task_runner_(resource_task_runner),
+      image_cursors_set_weak_ptr_(image_cursors_set_weak_ptr),
+      weak_ptr_factory_(this) {
+  DCHECK(resource_task_runner_);
+  ui_service_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+
+  // Create and initialize the ImageCursors object here and then set it on
+  // |image_cursors_set_weak_ptr__|. Note that it is essential to initialize
+  // the ImageCursors object on the UI Service's thread if we are using Ozone,
+  // so that it uses the right (thread-local) CursorFactoryOzone instance.
+  std::unique_ptr<ui::ImageCursors> image_cursors =
+      base::MakeUnique<ui::ImageCursors>();
+  image_cursors->Initialize();
+  image_cursors_weak_ptr_ = image_cursors->GetWeakPtr();
+  resource_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&AddImageCursorsOnResourceThread, image_cursors_set_weak_ptr_,
+                 base::Passed(std::move(image_cursors))));
+}
+
+ThreadedImageCursors::~ThreadedImageCursors() {
+  resource_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RemoveImageCursorsOnResourceThread,
+                 image_cursors_set_weak_ptr_, image_cursors_weak_ptr_));
+}
+
+void ThreadedImageCursors::SetDisplay(const display::Display& display,
+                                      float scale_factor) {
+  resource_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&SetDisplayOnResourceThread,
+                            image_cursors_weak_ptr_, display, scale_factor));
+}
+
+void ThreadedImageCursors::SetCursorSize(CursorSize cursor_size) {
+  resource_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&SetCursorSizeOnResourceThread,
+                            image_cursors_weak_ptr_, cursor_size));
+}
+
+void ThreadedImageCursors::SetCursor(ui::CursorType cursor_type,
+                                     ui::PlatformWindow* platform_window) {
+  resource_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&SetCursorOnResourceThread, image_cursors_weak_ptr_,
+                 cursor_type, platform_window, ui_service_task_runner_,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ThreadedImageCursors::SetCursorOnPlatformWindow(
+    ui::PlatformCursor platform_cursor,
+    ui::PlatformWindow* platform_window) {
+  platform_window->SetCursor(platform_cursor);
+}
+
+}  // namespace ws
+}  // namespace ui