Misc cleanups in Drive code.

chrome/browser/google_apis/base_operations.h

Index: chrome/browser/google_apis/base_operations.h
diff --git a/chrome/browser/google_apis/base_operations.h b/chrome/browser/google_apis/base_operations.h
index 0b1d1ca7da4c64e8ae670d1dd27f01ed61e835fd..885264c288194730929ccd425d55def4eb2eba44 100644
--- a/chrome/browser/google_apis/base_operations.h
+++ b/chrome/browser/google_apis/base_operations.h
@@ -15,13 +15,10 @@
 #include "chrome/browser/google_apis/drive_upload_mode.h"
 #include "chrome/browser/google_apis/gdata_errorcode.h"
 #include "chrome/browser/google_apis/operation_registry.h"
-#include "google_apis/gaia/oauth2_access_token_consumer.h"
 #include "googleurl/src/gurl.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 
-class OAuth2AccessTokenFetcher;
-
 namespace base {
 class Value;
 }  // namespace base
@@ -32,7 +29,7 @@ class URLRequestContextGetter;
 
 namespace google_apis {
 
-// Callback used to pass parsed JSON from ParseJson(). If parsing error occures,
+// Callback used to pass parsed JSON from ParseJson(). If parsing error occurs,
 // then the passed argument is null.
 typedef base::Callback<void(scoped_ptr<base::Value> value)> ParseJsonCallback;