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/dbus_utils.cc b/buffet/dbus_utils.cc
index 4924ef5..58f0b26 100644
--- a/buffet/dbus_utils.cc
+++ b/buffet/dbus_utils.cc
@@ -38,7 +38,7 @@
 }
 
 scoped_ptr<dbus::Response> GetDBusError(dbus::MethodCall* method_call,
-                                        const chromeos::Error* error) {
+                                        const Error* error) {
   std::string message;
   while (error) {
     // Format error string as "domain/code:message".