tracing: add dump provider for malloc heap profiler

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 63fc1b082677edef4157f57b8cd6f9951cec7a80..d9d702176a44057ea4fcb04f1aca4c844ac45d24 100644
--- a/base/trace_event/malloc_dump_provider.h
+++ b/base/trace_event/malloc_dump_provider.h
@@ -8,7 +8,10 @@
 #include <istream>
 
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.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"
 
@@ -20,6 +23,8 @@
 namespace base {
 namespace trace_event {
 
+class AllocationRegister;
+
 // Dump provider which collects process-wide memory stats.
 class BASE_EXPORT MallocDumpProvider : public MemoryDumpProvider {
  public:
@@ -33,12 +38,28 @@ class BASE_EXPORT MallocDumpProvider : public MemoryDumpProvider {
   bool OnMemoryDump(const MemoryDumpArgs& args,
                     ProcessMemoryDump* pmd) override;
 
+  void OnHeapProfilingEnabled(bool enabled) override;
+
+  // For heap profiling.
+  void InsertAllocation(void* address, size_t size);
+  void RemoveAllocation(void* address);
+
  private:
   friend struct DefaultSingletonTraits<MallocDumpProvider>;
 
   MallocDumpProvider();
   ~MallocDumpProvider() override;
 
+  // For heap profiling.
+  bool heap_profiler_enabled_;
+  scoped_ptr<AllocationRegister> allocation_register_;
+  Lock allocation_register_lock_;
+
+  // When in OnMemoryDump(), this contains the current thread ID.
+  // This is to prevent re-entrancy in the heap profiler when the heap dump
+  // generation is malloc/new-ing for its own bookeeping data structures.
+  PlatformThreadId tid_dumping_heap_;
+
   DISALLOW_COPY_AND_ASSIGN(MallocDumpProvider);
 };