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 50aea244124d426967e822902758c962a8cebabe..d3899bd64869d4a51e886e5bc7821f0b6e0c69e1 100644
--- a/components/data_reduction_proxy/common/data_reduction_proxy_headers.h
+++ b/components/data_reduction_proxy/common/data_reduction_proxy_headers.h
@@ -16,6 +16,11 @@ using net::ProxyService;
 
 namespace data_reduction_proxy {
 
+extern const char kChromeProxyActionFingerprintChromeProxy[];
+extern const char kChromeProxyActionFingerprintVia[];
+extern const char kChromeProxyActionFingerprintOtherHeaders[];
+extern const char kChromeProxyActionFingerprintContentLength[];
+
 // Contains instructions contained in the Chrome-Proxy header.
 struct DataReductionProxyInfo {
   DataReductionProxyInfo() : bypass_all(false) {}
@@ -39,8 +44,12 @@ bool GetDataReductionProxyInfo(
     DataReductionProxyInfo* proxy_info);
 
 // Returns true if the response contain the data reduction proxy Via header

[bengr, 2014/07/29 17:50:28]

contains

[xingx1, 2014/07/30 03:32:56]

Done.

-// 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 data reduction proxy and chrome.

[bengr, 2014/07/29 17:50:28]

data --> the data
chrome --> the client

[xingx1, 2014/07/30 03:32:56]

Done.

+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
@@ -49,6 +58,14 @@ 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 GetDataReductionProxyBypassDuration(