buffet: Remove 'chromeos' namespace and move everything to buffet NS

As discussed, moved all the classes out of chromeos namespace into
'buffet.

Also fixed a number of cpplint's warnings.

BUG=None
TEST=Everything still compiles and unit tests succeed.

Change-Id: Ide864acb2504627404966727f66d353af60e531d
Reviewed-on: https://chromium-review.googlesource.com/198971
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/buffet/manager.cc b/buffet/manager.cc
index 2195b83..09985b3 100644
--- a/buffet/manager.cc
+++ b/buffet/manager.cc
@@ -127,7 +127,7 @@
 
   LOG(INFO) << "Received call to Manager.CheckDeviceRegistered()";
 
-  chromeos::ErrorPtr error;
+  buffet::ErrorPtr error;
   bool registered = device_info_.CheckRegistration(&error);
   // If it fails due to any reason other than 'device not registered',
   // treat it as a real error and report it to the caller.
@@ -162,7 +162,7 @@
   LOG(INFO) << "Received call to Manager.GetDeviceInfo()";
 
   std::string device_info_str;
-  chromeos::ErrorPtr error;
+  buffet::ErrorPtr error;
   auto device_info = device_info_.GetDeviceInfo(&error);
   if (!device_info)
     return GetDBusError(method_call, error.get());
@@ -207,7 +207,7 @@
 
   LOG(INFO) << "Received call to Manager.StartRegisterDevice()";
 
-  chromeos::ErrorPtr error;
+  buffet::ErrorPtr error;
   std::string id = device_info_.StartRegistration(params, &error);
   if (id.empty())
     return GetDBusError(method_call, error.get());
@@ -238,7 +238,7 @@
   }
 
   LOG(INFO) << "Received call to Manager.FinishRegisterDevice()";
-  chromeos::ErrorPtr error;
+  buffet::ErrorPtr error;
   if (!device_info_.FinishRegistration(user_auth_code, &error))
     return GetDBusError(method_call, error.get());