Replace base::str[n]casecmp with helper functions.

chrome/browser/net/sdch_browsertest.cc

Index: chrome/browser/net/sdch_browsertest.cc
diff --git a/chrome/browser/net/sdch_browsertest.cc b/chrome/browser/net/sdch_browsertest.cc
index 7a1cb7b69211d697e86a68cd7e59376138ae01aa..9c93d6b841dda2a74a62edc80a7e47aa3af5d16e 100644
--- a/chrome/browser/net/sdch_browsertest.cc
+++ b/chrome/browser/net/sdch_browsertest.cc
@@ -108,7 +108,7 @@ bool GetRequestHeader(const HttpRequestHeaderMap& map,
                       std::string* value) {
   for (HttpRequestHeaderMap::const_iterator it = map.begin();
        it != map.end(); ++it) {
-    if (!base::strcasecmp(it->first.c_str(), header)) {
+    if (base::EqualsCaseInsensitiveASCII(it->first, header)) {
       *value = it->second;
       return true;
     }
@@ -170,7 +170,7 @@ class SdchResponseHandler {
       return false;
     base::StringTokenizer tokenizer(value, " ,");
     while (tokenizer.GetNext()) {
-      if (base::strcasecmp(tokenizer.token().c_str(), "sdch"))
+      if (base::EqualsCaseInsensitiveASCII(tokenizer.token(), "sdch"))
         return true;
     }
     return false;