3 files changed, 34 insertions, 0 deletions
diff --git a/net/http/http_util.cc b/net/http/http_util.cc
index 811d7b0..72c7737e 100644
--- a/net/http/http_util.cc
+++ b/net/http/http_util.cc
@@ -642,6 +642,20 @@ bool HttpUtil::HeadersIterator::GetNext() {
   return false;
 }
 
+bool HttpUtil::HeadersIterator::AdvanceTo(const char* name) {
+  DCHECK(name != NULL);
+  DCHECK_EQ(0, StringToLowerASCII<std::string>(name).compare(name))
+      << "the header name must be in all lower case";
+
+  while (GetNext()) {
+    if (LowerCaseEqualsASCII(name_begin_, name_end_, name)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 HttpUtil::ValuesIterator::ValuesIterator(
     string::const_iterator values_begin,
     string::const_iterator values_end,
diff --git a/net/http/http_util.h b/net/http/http_util.h
index ad7e671..fcf762d9 100644
--- a/net/http/http_util.h
+++ b/net/http/http_util.h
@@ -159,6 +159,14 @@ class HttpUtil {
     // header name and values.
     bool GetNext();
 
+    // Iterates through the list of headers, starting with the current position
+    // and looks for the specified header.  Note that the name _must_ be
+    // lower cased.
+    // If the header was found, the return value will be true and the current
+    // position points to the header.  If the return value is false, the
+    // current position will be at the end of the headers.
+    bool AdvanceTo(const char* lowercase_name);
+
     std::string::const_iterator name_begin() const {
       return name_begin_;
     }
diff --git a/net/http/http_util_unittest.cc b/net/http/http_util_unittest.cc
index 11e3fa3..80413ac 100644
--- a/net/http/http_util_unittest.cc
+++ b/net/http/http_util_unittest.cc
@@ -93,6 +93,18 @@ TEST(HttpUtilTest, HeadersIterator_MalformedLine) {
   EXPECT_FALSE(it.GetNext());
 }
 
+TEST(HttpUtilTest, HeadersIterator_AdvanceTo) {
+  std::string headers = "foo: 1\r\n: 2\r\n3\r\nbar: 4";
+
+  HttpUtil::HeadersIterator it(headers.begin(), headers.end(), "\r\n");
+  EXPECT_TRUE(it.AdvanceTo("foo"));
+  EXPECT_EQ("foo", it.name());
+  EXPECT_TRUE(it.AdvanceTo("bar"));
+  EXPECT_EQ("bar", it.name());
+  EXPECT_FALSE(it.AdvanceTo("blat"));
+  EXPECT_FALSE(it.GetNext());  // should be at end of headers
+}
+
 TEST(HttpUtilTest, ValuesIterator) {
   std::string values = " must-revalidate,   no-cache=\"foo, bar\"\t, private ";