[tracing] Don't use moved value.

This CL fixes an issue where we use std::unique_ptr<> after explicitly
moving it into a map.

Review-Url: https://codereview.chromium.org/1932733003
Cr-Commit-Position: refs/heads/master@{#390745}


CrOS-Libchrome-Original-Commit: d20680c83c603d50678a6be1e1f389c25783ea86
diff --git a/base/trace_event/process_memory_dump.cc b/base/trace_event/process_memory_dump.cc
index 56fda80..902f9d4 100644
--- a/base/trace_event/process_memory_dump.cc
+++ b/base/trace_event/process_memory_dump.cc
@@ -170,8 +170,10 @@
     std::unique_ptr<MemoryAllocatorDump> mad) {
   auto insertion_result = allocator_dumps_.insert(
       std::make_pair(mad->absolute_name(), std::move(mad)));
-  DCHECK(insertion_result.second) << "Duplicate name: " << mad->absolute_name();
-  return insertion_result.first->second.get();
+  MemoryAllocatorDump* inserted_mad = insertion_result.first->second.get();
+  DCHECK(insertion_result.second) << "Duplicate name: "
+                                  << inserted_mad->absolute_name();
+  return inserted_mad;
 }
 
 MemoryAllocatorDump* ProcessMemoryDump::GetAllocatorDump(