Modify data_reduction_proxy_header to support tamper detection logic.

components/data_reduction_proxy/common/data_reduction_proxy_headers.h

Index: components/data_reduction_proxy/common/data_reduction_proxy_headers.h
diff --git a/components/data_reduction_proxy/common/data_reduction_proxy_headers.h b/components/data_reduction_proxy/common/data_reduction_proxy_headers.h
index 28eccee3073e6c84e4779a338e6e36eb035761e9..319d90da8194c7aa26267192c38f326da497fb1d 100644
--- a/components/data_reduction_proxy/common/data_reduction_proxy_headers.h
+++ b/components/data_reduction_proxy/common/data_reduction_proxy_headers.h
@@ -41,8 +41,12 @@ bool ParseHeadersAndSetProxyInfo(const net::HttpResponseHeaders* headers,
                                  DataReductionProxyInfo* proxy_info);
 
 // Returns true if the response contains the data reduction proxy Via header
-// value. Used to check the integrity of data reduction proxy responses.
-bool HasDataReductionProxyViaHeader(const net::HttpResponseHeaders* headers);
+// value. If non-NULL, sets |has_intermediary| to true if another server added
+// a Via header after the data reduction proxy, and to false otherwise. Used to
+// check the integrity of data reduction proxy responses and whether there are
+// other middleboxes between the data reduction proxy and the client.
+bool HasDataReductionProxyViaHeader(const net::HttpResponseHeaders* headers,
+                                    bool* has_intermediary);
 
 // Returns the reason why the Chrome proxy should be bypassed or not, and
 // populates |proxy_info| with information on how long to bypass if
@@ -51,11 +55,44 @@ net::ProxyService::DataReductionProxyBypassType GetDataReductionProxyBypassType(
     const net::HttpResponseHeaders* headers,
     DataReductionProxyInfo* proxy_info);
 
+// Searches for the specified Chrome-Proxy action, and if present saves its
+// value as a string in |action_value|. Only returns the first one and ignores
+// the rest if multiple actions match |action_prefix|.
+bool GetDataReductionProxyActionValue(
+    const net::HttpResponseHeaders* headers,
+    const std::string& action_prefix,
+    std::string* action_value);
+
 // Searches for the specified Chrome-Proxy action, and if present interprets
 // its value as a duration in seconds.
 bool ParseHeadersAndSetBypassDuration(const net::HttpResponseHeaders* headers,
                                       const std::string& action_prefix,
                                       base::TimeDelta* bypass_duration);
 
+// Gets the fingerprint of the Chrome-Proxy header.
+bool GetDataReductionProxyActionFingerprintChromeProxy(
+    const net::HttpResponseHeaders* headers,
+    std::string* chrome_proxy_fingerprint);
+
+// Gets the fingerprint of the Via header.
+bool GetDataReductionProxyActionFingerprintVia(
+    const net::HttpResponseHeaders* headers,
+    std::string* via_fingerprint);
+
+// Gets the fingerprint of a list of headers.
+bool GetDataReductionProxyActionFingerprintOtherHeaders(
+    const net::HttpResponseHeaders* headers,
+    std::string* other_headers_fingerprint);
+
+// Gets the fingerprint of Content-Length header.
+bool GetDataReductionProxyActionFingerprintContentLength(
+    const net::HttpResponseHeaders* headers,
+    std::string* content_length_fingerprint);
+
+// Returns values of the Chrome-Proxy header, but with its fingerprint removed.
+void GetDataReductionProxyHeaderWithFingerprintRemoved(
+    const net::HttpResponseHeaders* headers,
+    std::vector<std::string>* values);
+
 }  // namespace data_reduction_proxy
 #endif  // COMPONENTS_DATA_REDUCTION_PROXY_COMMON_DATA_REDUCTION_PROXY_HEADERS_H_