Move UsbService to its own component.

components/usb_service/usb_context.h

Index: components/usb_service/usb_context.h
diff --git a/chrome/browser/usb/usb_context.h b/components/usb_service/usb_context.h
similarity index 74%
rename from chrome/browser/usb/usb_context.h
rename to components/usb_service/usb_context.h
index c9142069c5206e9a9de6a4928a9ce988e4e79844..ad6c4166ac40bba4ec6b905e36b6d0d634c504cc 100644
--- a/chrome/browser/usb/usb_context.h
+++ b/components/usb_service/usb_context.h
@@ -2,23 +2,27 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_USB_USB_CONTEXT_H_
-#define CHROME_BROWSER_USB_USB_CONTEXT_H_
+#ifndef COMPONENTS_USB_SERVICE_USB_CONTEXT_H_
+#define COMPONENTS_USB_SERVICE_USB_CONTEXT_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread_checker.h"
+#include "components/usb_service/usb_service_export.h"
 
 struct libusb_context;
 
+namespace usb_service {
+
 typedef libusb_context* PlatformUsbContext;
 
 // Ref-counted wrapper for libusb_context*.
 // It also manages the life-cycle of UsbEventHandler.
 // It is a blocking operation to delete UsbContext.
 // Destructor must be called on FILE thread.
-class UsbContext : public base::RefCountedThreadSafe<UsbContext> {
+class USB_SERVICE_EXPORT UsbContext
+    : public base::RefCountedThreadSafe<UsbContext> {
  public:
   PlatformUsbContext context() const { return context_; }
 
@@ -38,4 +42,6 @@ class UsbContext : public base::RefCountedThreadSafe<UsbContext> {
   DISALLOW_COPY_AND_ASSIGN(UsbContext);
 };
 
-#endif  // CHROME_BROWSER_USB_USB_CONTEXT_H_
+}  // namespace usb_service
+
+#endif  // COMPONENTS_USB_SERVICE_USB_CONTEXT_H_