Fix CompositorResizeLock to do something.

ui/compositor/compositor_lock.cc

Index: ui/compositor/compositor_lock.cc
diff --git a/ui/compositor/compositor_lock.cc b/ui/compositor/compositor_lock.cc
new file mode 100644
index 0000000000000000000000000000000000000000..542afbc1862b011dec52a6abbc2dc305285ea63f
--- /dev/null
+++ b/ui/compositor/compositor_lock.cc
@@ -0,0 +1,39 @@
+// 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 "ui/compositor/compositor_lock.h"
+
+#include "base/bind.h"
+#include "base/sequenced_task_runner.h"
+#include "base/task_runner.h"
+#include "ui/compositor/compositor.h"
+
+namespace ui {
+
+CompositorLock::CompositorLock(CompositorLockClient* client,
+                               CompositorLockDelegate* delegate,
+                               base::SequencedTaskRunner* task_runner,
+                               base::TimeDelta timeout)
+    : client_(client), delegate_(std::move(delegate)), weak_ptr_factory_(this) {
+  if (!timeout.is_zero()) {
+    task_runner->PostDelayedTask(FROM_HERE,
+                                 base::Bind(&CompositorLock::TimeoutLock,
+                                            weak_ptr_factory_.GetWeakPtr()),
+                                 timeout);
+  }
+}
+
+CompositorLock::~CompositorLock() {
+  if (delegate_)
+    delegate_->DoUnlockCompositor();
+}
+
+void CompositorLock::TimeoutLock() {
+  delegate_->DoUnlockCompositor();
+  delegate_ = nullptr;
+  if (client_)
+    client_->CompositorLockTimedOut();
+}
+
+}  // namespace ui