Replace base::SharedMemory read-only methods with GetReadOnlyHandle.

base/memory/shared_memory_nacl.cc

Index: base/memory/shared_memory_nacl.cc
diff --git a/base/memory/shared_memory_nacl.cc b/base/memory/shared_memory_nacl.cc
index 670ade5ff34273e719affa5c1ea030d4bb0f252b..32c321068158d5c3fa4e8228e9bdb8c91e27a78a 100644
--- a/base/memory/shared_memory_nacl.cc
+++ b/base/memory/shared_memory_nacl.cc
@@ -125,18 +125,16 @@ void SharedMemory::Close() {
   }
 }
 
-bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
-                                        SharedMemoryHandle *new_handle,
-                                        bool close_self,
-                                        ShareMode share_mode) {
-  if (share_mode == SHARE_READONLY) {
-    // Untrusted code can't create descriptors or handles, which is needed to
-    // drop permissions.
-    return false;
-  }
+SharedMemoryHandle SharedMemory::GetReadOnlyHandle() {
+  // Untrusted code can't create descriptors or handles, which is needed to
+  // drop permissions.
+  return SharedMemoryHandle();
+}
 
+bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
+                                        SharedMemoryHandle* new_handle,
+                                        bool close_self) {
   *new_handle = shm_.Duplicate();
-
   if (close_self) {
     Unmap();
     Close();