Introduced AndroidDeviceProvider to simplify testing.

chrome/browser/devtools/refcounted_adb_thread.cc

+// Copyright (c) 2013 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 "chrome/browser/devtools/refcounted_adb_thread.h"
+
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+const char kDevToolsAdbBridgeThreadName[] = "Chrome_DevToolsADBThread";
+
+RefCountedAdbThread* RefCountedAdbThread::instance_ = NULL;
+
+// static
+scoped_refptr<RefCountedAdbThread> RefCountedAdbThread::GetInstance() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!instance_)
+    new RefCountedAdbThread();
+  return instance_;
+}
+
+RefCountedAdbThread::RefCountedAdbThread() {
+  instance_ = this;
+  thread_ = new base::Thread(kDevToolsAdbBridgeThreadName);
+  base::Thread::Options options;
+  options.message_loop_type = base::MessageLoop::TYPE_IO;
+  if (!thread_->StartWithOptions(options)) {
+    delete thread_;
+    thread_ = NULL;
+  }
+}
+
+base::MessageLoop* RefCountedAdbThread::message_loop() {
+  return thread_ ? thread_->message_loop() : NULL;
+}
+
+// static
+void RefCountedAdbThread::StopThread(base::Thread* thread) {
+  thread->Stop();
+}
+
+RefCountedAdbThread::~RefCountedAdbThread() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  instance_ = NULL;
+  if (!thread_)
+    return;
+  // Shut down thread on FILE thread to join into IO.
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&RefCountedAdbThread::StopThread, thread_));
+}