remove implementation of obsolete WebKitPlatformSupport::prefetchHostName.

content/renderer/renderer_webkitplatformsupport_impl.cc

Index: content/renderer/renderer_webkitplatformsupport_impl.cc
diff --git a/content/renderer/renderer_webkitplatformsupport_impl.cc b/content/renderer/renderer_webkitplatformsupport_impl.cc
index 007e1452bdf92fdc84ce7b7449c8724952a25cfb..e4cdfef7009f1feda48081c16fe0c48c1669b476 100644
--- a/content/renderer/renderer_webkitplatformsupport_impl.cc
+++ b/content/renderer/renderer_webkitplatformsupport_impl.cc
@@ -321,16 +321,6 @@ RendererWebKitPlatformSupportImpl::createMessagePortChannel() {
   return new WebMessagePortChannelImpl(child_thread_loop_.get());
 }
 
-void RendererWebKitPlatformSupportImpl::prefetchHostName(
-    const WebString& hostname) {
-  if (hostname.isEmpty())
-    return;
-
-  std::string hostname_utf8 = UTF16ToUTF8(hostname);
-  GetContentClient()->renderer()->PrefetchHostName(
-      hostname_utf8.data(), hostname_utf8.length());
-}
-
 WebKit::WebPrescientNetworking*
 RendererWebKitPlatformSupportImpl::prescientNetworking() {
   return GetContentClient()->renderer()->GetPrescientNetworking();