Support for new data reduction proxy via header

net/http/http_network_transaction.cc

Index: net/http/http_network_transaction.cc
diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index 96817e2b14fa2c1bb96ff827015943e96c6aedf0..6561a0aad23e47ac9dbc210888868f1247cd0b79 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -126,19 +126,28 @@ bool IsChromeProxyResponse(const net::HttpResponseHeaders* response_headers) {
   if (!response_headers) {
     return false;
   }
-  const char kDataReductionProxyViaValue[] = "1.1 Chrome Compression Proxy";
+
+  const size_t kVersionSize = 4;
+  const char kDataReductionProxyViaValue[] = "Chrome-Compression-Proxy";
   size_t value_len = strlen(kDataReductionProxyViaValue);
   void* iter = NULL;
-  std::string temp;
-  while (response_headers->EnumerateHeader(&iter, "Via", &temp)) {
-    std::string::const_iterator it =
-        std::search(temp.begin(), temp.end(),
-                    kDataReductionProxyViaValue,
-                    kDataReductionProxyViaValue + value_len,
-                    base::CaseInsensitiveCompareASCII<char>());
-    if (it != temp.end())
+  std::string value;
+
+  // Case-sensitive comparison. Assumes the received protocol and the space
+  // following it are always |kVersionSize| characters. E.g.,
+  // 'Via: 1.1 Chrome-Compression-Proxy'
+  while (response_headers->EnumerateHeader(&iter, "via", &value)) {
+    if (!value.compare(kVersionSize, value_len, kDataReductionProxyViaValue))
       return true;
   }
+
+  // TODO(bengr): Remove deprecated header value.
+  const char kDeprecatedDataReductionProxyViaValue[] =
+      "1.1 Chrome Compression Proxy";
+  iter = NULL;
+  while (response_headers->EnumerateHeader(&iter, "via", &value))
+    if (value == kDeprecatedDataReductionProxyViaValue) return true;
+
   return false;
 }
 #endif