content: Some code cleanup related to shared memory allocation.

content/child/child_thread_impl.cc

Index: content/child/child_thread_impl.cc
diff --git a/content/child/child_thread_impl.cc b/content/child/child_thread_impl.cc
index 7f2755b3e00f3859bfe499adb57561c2686db6ca..a07a1f10c393092bd8fada27f2bcdca1ed7faafa 100644
--- a/content/child/child_thread_impl.cc
+++ b/content/child/child_thread_impl.cc
@@ -721,16 +721,9 @@ mojom::RouteProvider* ChildThreadImpl::GetRemoteRouteProvider() {
   return remote_route_provider_.get();
 }
 
-std::unique_ptr<base::SharedMemory> ChildThreadImpl::AllocateSharedMemory(
-    size_t buf_size) {
-  DCHECK(message_loop_->task_runner()->BelongsToCurrentThread());
-  return AllocateSharedMemory(buf_size, this, nullptr);
-}
-
 // static
 std::unique_ptr<base::SharedMemory> ChildThreadImpl::AllocateSharedMemory(
     size_t buf_size,
-    IPC::Sender* sender,
     bool* out_of_memory) {
   mojo::ScopedSharedBufferHandle mojo_buf =
       mojo::SharedBufferHandle::Create(buf_size);