[GCM] Use the correct content type to talk with server for all users

components/gcm_driver/gcm_channel_status_request.cc

Index: components/gcm_driver/gcm_channel_status_request.cc
diff --git a/components/gcm_driver/gcm_channel_status_request.cc b/components/gcm_driver/gcm_channel_status_request.cc
index a027a7f17a9d3d4f4726665c581482bbd30c3f24..206ee39899e95225dfcdbeed00080366eeb31110 100644
--- a/components/gcm_driver/gcm_channel_status_request.cc
+++ b/components/gcm_driver/gcm_channel_status_request.cc
@@ -21,7 +21,7 @@ namespace {
 
 const char kGCMChannelStatusRequestURL[] =
     "https://clients4.google.com/chrome-sync/command/";
-const char kRequestContentType[] = "application/x-protobuf";
+const char kRequestContentType[] = "application/octet-stream";
 const char kGCMChannelTag[] = "gcm_channel";
 const int kDefaultPollIntervalSeconds = 60 * 60;  // 60 minutes.
 const int kMinPollIntervalSeconds = 30 * 60;  // 30 minutes.