[ServiceWorker] Don't send the UMA related headers to the ServiceWorker.

content/public/browser/service_worker_context.h

Index: content/public/browser/service_worker_context.h
diff --git a/content/public/browser/service_worker_context.h b/content/public/browser/service_worker_context.h
index e035fbec34ed0a4213bce2dcce0ffdae2c55f83a..518428adc0f6394cbe884d1157d5632ecb0e6ca7 100644
--- a/content/public/browser/service_worker_context.h
+++ b/content/public/browser/service_worker_context.h
@@ -5,6 +5,10 @@
 #ifndef CONTENT_PUBLIC_BROWSER_SERVICE_WORKER_CONTEXT_H_
 #define CONTENT_PUBLIC_BROWSER_SERVICE_WORKER_CONTEXT_H_
 
+#include <set>
+#include <string>
+#include <vector>
+
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "content/public/browser/service_worker_usage_info.h"
@@ -13,7 +17,7 @@
 namespace content {
 
 // Represents the per-StoragePartition ServiceWorker data.  Must be used from
-// the IO thread.
+// the IO thread except for AddExcludedHeaderNameForFetchEvent.
 class ServiceWorkerContext {
  public:
   // https://rawgithub.com/slightlyoff/ServiceWorker/master/spec/service_worker/index.html#url-scope:
@@ -25,6 +29,13 @@ class ServiceWorkerContext {
   typedef base::Callback<void(const std::vector<ServiceWorkerUsageInfo>&
                                   usage_info)> GetUsageInfoCallback;
 
+  // Registers the header name which should not be passed to the ServiceWorker.
+  CONTENT_EXPORT static void AddExcludedHeaderNameForFetchEvent(
+      const std::string& header_name);
+
+  // Returns true if the header name should not be passed to the ServiceWorker.
+  static bool IsExcludedHeaderNameForFetchEvent(const std::string& header_name);
+
   // Equivalent to calling navigator.serviceWorker.register(script_url, {scope:
   // pattern}) from a renderer, except that |pattern| is an absolute URL instead
   // of relative to some current origin.  |callback| is passed true when the JS