Enable sharding of AllocationRegister on desktop.

base/trace_event/malloc_dump_provider.h

Index: base/trace_event/malloc_dump_provider.h
diff --git a/base/trace_event/malloc_dump_provider.h b/base/trace_event/malloc_dump_provider.h
index 384033c9b82abc55125405e9a29ede7aa9597c08..6c8d3b8681690336babed8ae6e0f6df9b4c125ce 100644
--- a/base/trace_event/malloc_dump_provider.h
+++ b/base/trace_event/malloc_dump_provider.h
@@ -10,7 +10,6 @@
 
 #include "base/macros.h"
 #include "base/memory/singleton.h"
-#include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "build/build_config.h"
@@ -23,7 +22,7 @@
 namespace base {
 namespace trace_event {
 
-class AllocationRegister;
+class ShardedAllocationRegister;
 
 // Dump provider which collects process-wide memory stats.
 class BASE_EXPORT MallocDumpProvider : public MemoryDumpProvider {
@@ -51,9 +50,7 @@ class BASE_EXPORT MallocDumpProvider : public MemoryDumpProvider {
   ~MallocDumpProvider() override;
 
   // For heap profiling.
-  bool heap_profiler_enabled_;
-  std::unique_ptr<AllocationRegister> allocation_register_;
-  Lock allocation_register_lock_;
+  std::unique_ptr<ShardedAllocationRegister> allocation_register_;

[Primiano Tucci (use gerrit), 2017/05/22 16:37:50]

there is no need for a unique_ptr anymore here now, this could just be a field,
right?

[erikchen, 2017/05/22 17:10:42]

Done.

 
   // When in OnMemoryDump(), this contains the current thread ID.
   // This is to prevent re-entrancy in the heap profiler when the heap dump