Move UsbService to its own component.

components/usb_service/usb_context_unittest.cc

 // Copyright 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/usb/usb_context.h"
-
 #include "base/threading/platform_thread.h"
 #include "build/build_config.h"
+#include "components/usb_service/usb_context.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/libusb/src/libusb/libusb.h"
 
+using usb_service::UsbContext;
+using usb_service::PlatformUsbContext;
+
 namespace {
 
 class UsbContextTest : public testing::Test {
  protected:
   class UsbContextForTest : public UsbContext {
    public:
     explicit UsbContextForTest(PlatformUsbContext context)
         : UsbContext(context) {}
+
    private:
     virtual ~UsbContextForTest() {}
     DISALLOW_COPY_AND_ASSIGN(UsbContextForTest);
   };
 };
 
 }  // namespace
 
 #if defined(OS_LINUX)
 // Linux trybot does not support usb.
@@ skipping 11 matching lines @@
     PlatformUsbContext platform_context;
     ASSERT_EQ(LIBUSB_SUCCESS, libusb_init(&platform_context));
     scoped_refptr<UsbContextForTest> context(
         new UsbContextForTest(platform_context));
   }
   base::TimeDelta elapse = base::TimeTicks::Now() - start;
   if (elapse > base::TimeDelta::FromSeconds(2)) {
     FAIL();
   }
 }