Remove legacy StartsWithASCII function.

components/invalidation/impl/gcm_network_channel_unittest.cc

Index: components/invalidation/impl/gcm_network_channel_unittest.cc
diff --git a/components/invalidation/impl/gcm_network_channel_unittest.cc b/components/invalidation/impl/gcm_network_channel_unittest.cc
index 8efb2f47488f25606390796aa5b65e4a85bbd811..e07788e5e0d5d88a35f7ec9795d791b60b252899 100644
--- a/components/invalidation/impl/gcm_network_channel_unittest.cc
+++ b/components/invalidation/impl/gcm_network_channel_unittest.cc
@@ -233,7 +233,8 @@ void TestNetworkChannelURLFetcher::AddExtraRequestHeader(
   net::FakeURLFetcher::AddExtraRequestHeader(header_line);
   std::string header_name("echo-token: ");
   std::string echo_token;
-  if (base::StartsWithASCII(header_line, header_name, false)) {
+  if (base::StartsWith(header_line, header_name,
+                       base::CompareCase::INSENSITIVE_ASCII)) {
     echo_token = header_line;
     base::ReplaceFirstSubstringAfterOffset(
         &echo_token, 0, header_name, std::string());