Adding UsbService and UsbDevice constructs.

chrome/browser/profiles/profile.h

Index: chrome/browser/profiles/profile.h
diff --git a/chrome/browser/profiles/profile.h b/chrome/browser/profiles/profile.h
index 3492d9b19313f64dc11e33078bf4e46944db968d..feb643cde09e572eff8040ee75e6c8f150b39843 100644
--- a/chrome/browser/profiles/profile.h
+++ b/chrome/browser/profiles/profile.h
@@ -36,6 +36,7 @@ class PrefService;
 class PromoCounter;
 class ProtocolHandlerRegistry;
 class TestingProfile;
+class UsbService;
 class UserScriptMaster;
 class VisitedLinkMaster;
 class WebDataService;
@@ -395,6 +396,11 @@ class Profile : public content::BrowserContext {
   // more recent (or equal to) the one specified.
   virtual bool WasCreatedByVersionOrLater(const std::string& version) = 0;
 
+#if !defined(OS_ANDROID)

[sail, 2012/04/25 21:06:36]

it's a bad idea to have #ifdefs in code. The general approach is to define this
on all platform and implement a stub for android.

If this is not practical then another approach would be to move this ifdef to
only the profile_impl.cc file. This ways callers can do something like this:
  service = profile()->GetUsbService();
  // Service may not exists on some platforms.
  if (!service)
    return;

+  // Returns or creates and returns an instance of the UsbService.

[miket_OOO, 2012/04/25 21:24:36]

This is a minor point, but the "or creates and returns" feels like an
implementation detail that the caller shouldn't care about. Isn't "Returns..."
enough?

+  virtual UsbService* GetUsbService() = 0;
+#endif  // !defined(OS_ANDROID)
+
   std::string GetDebugName();
 
   // Returns whether it is a guest session.