Remove obsolete methods from IPC::Channel and related classes.

content/common/child_process_host_impl.cc

Index: content/common/child_process_host_impl.cc
diff --git a/content/common/child_process_host_impl.cc b/content/common/child_process_host_impl.cc
index 42f368d0ed1272b3ac7b67c529fbc6e19ab07e12..71a34fcc6d9e244060725270f20ecda6b6fa252a 100644
--- a/content/common/child_process_host_impl.cc
+++ b/content/common/child_process_host_impl.cc
@@ -177,12 +177,6 @@ bool ChildProcessHostImpl::IsChannelOpening() {
   return opening_channel_;
 }
 
-#if defined(OS_POSIX)
-base::ScopedFD ChildProcessHostImpl::TakeClientFileDescriptor() {
-  return channel_->TakeClientFileDescriptor();
-}
-#endif
-
 bool ChildProcessHostImpl::Send(IPC::Message* message) {
   if (!channel_) {
     delete message;