Add support for field trial group to relax missing via header bypass logic.

components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.h

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.h
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.h
index 1f0acc4a99ff1ae6c63f969564e87804221dc98d..a0cb781e39ca319dd0022eb801eab25fa6b16934 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.h
@@ -5,11 +5,13 @@
 #ifndef COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_INTERCEPTOR_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_INTERCEPTOR_H_
 
+#include "base/memory/scoped_ptr.h"
 #include "net/url_request/url_request_interceptor.h"
 
 namespace data_reduction_proxy {
 class DataReductionProxyEventStore;
 class DataReductionProxyParams;
+class DataReductionProxyBypassProtocol;
 class DataReductionProxyUsageStats;
 
 // Used to intercept responses that contain explicit and implicit signals
@@ -33,10 +35,9 @@ class DataReductionProxyInterceptor : public net::URLRequestInterceptor {
       net::NetworkDelegate* network_delegate) const override;
 
   // Returns a new URLRequestHTTPJob if the response indicates that the data
-  // reduction proxy should be bypassed according to the rules in
-  // data_reduction_proxy_protocol.cc. Returns NULL otherwise. If a job is
-  // returned, the interceptor's URLRequestInterceptingJobFactory will restart
-  // the request.
+  // reduction proxy should be bypassed according to the rules in |protocol_|.
+  // Returns NULL otherwise. If a job is returned, the interceptor's
+  // URLRequestInterceptingJobFactory will restart the request.
   net::URLRequestJob* MaybeInterceptResponse(
       net::URLRequest* request,
       net::NetworkDelegate* network_delegate) const override;
@@ -51,6 +52,11 @@ class DataReductionProxyInterceptor : public net::URLRequestInterceptor {
   // Must outlive |this|.
   DataReductionProxyEventStore* event_store_;
 
+  // Object responsible for identifying cases when a response should cause the
+  // data reduction proxy to be bypassed, and for triggering proxy bypasses in
+  // these cases.
+  scoped_ptr<DataReductionProxyBypassProtocol> bypass_protocol_;
+
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyInterceptor);
 };