Implement basic USB device enumeration on Android.

chrome/browser/devtools/device/usb/android_usb_browsertest.cc

 // Copyright 2014 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 <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 
 #include "base/containers/scoped_ptr_hash_map.h"
@@ skipping 409 matching lines @@
   void Open(const OpenCallback& callback) override {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(callback, make_scoped_refptr(
                                             new MockUsbDeviceHandle<T>(this))));
   }
 
   const UsbConfigDescriptor* GetActiveConfiguration() override {
     return T::kConfigured ? &config_desc_ : nullptr;
   }
 
-  bool Close(scoped_refptr<UsbDeviceHandle> handle) override {
-    return true;
-  }
-
   std::set<int> claimed_interfaces_;
 
  protected:
   virtual ~MockUsbDevice() {}
 
  private:
   UsbConfigDescriptor config_desc_;
 };
 
 class MockUsbService : public UsbService {
@@ skipping 355 matching lines @@
   EXPECT_EQ(2, listener.invoked_);
   EXPECT_EQ(listener.invoked_ - 1, scheduler_invoked_);
   EXPECT_TRUE(base::MessageLoop::current()->IsIdleForTesting());
 }
 
 IN_PROC_BROWSER_TEST_F(AndroidUsbTraitsTest, TestDeviceCounting) {
   MockCountListenerForCheckingTraits listener(adb_bridge_);
   adb_bridge_->AddDeviceCountListener(&listener);
   runner_->Run();
 }