remove implementation of obsolete WebKitPlatformSupport::prefetchHostName.

android_webview/renderer/aw_content_renderer_client.cc

Index: android_webview/renderer/aw_content_renderer_client.cc
diff --git a/android_webview/renderer/aw_content_renderer_client.cc b/android_webview/renderer/aw_content_renderer_client.cc
index e3d240fb8f9745268c4755567915808d082f1355..92e3625a906d38bf937b8f7eb36dfb47ae44ef9f 100644
--- a/android_webview/renderer/aw_content_renderer_client.cc
+++ b/android_webview/renderer/aw_content_renderer_client.cc
@@ -102,10 +102,4 @@ bool AwContentRendererClient::IsLinkVisited(unsigned long long link_hash) {
   return visited_link_slave_->IsVisited(link_hash);
 }
 
-void AwContentRendererClient::PrefetchHostName(const char* hostname,
-                                               size_t length) {
-  // TODO(boliu): Implement hostname prefetch for Android WebView.
-  // Perhaps componentize chrome implementation or move to content/?
-}
-
 }  // namespace android_webview