[WIP] Add SharedMemoryTracker to dump base::SharedMemory usage

base/memory/shared_memory_posix.cc

Index: base/memory/shared_memory_posix.cc
diff --git a/base/memory/shared_memory_posix.cc b/base/memory/shared_memory_posix.cc
index 3a18faa83dd70e82c8381d33cc247afa270339a9..dfefbe3d20bd12163423cd8cb8bc325e3e84cb9a 100644
--- a/base/memory/shared_memory_posix.cc
+++ b/base/memory/shared_memory_posix.cc
@@ -15,6 +15,7 @@
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/memory/shared_memory_helper.h"
+#include "base/memory/shared_memory_tracker.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/posix/safe_strerror.h"
 #include "base/process/process_metrics.h"
@@ -284,7 +285,9 @@ bool SharedMemory::MapAt(off_t offset, size_t bytes) {
   if (mmap_succeeded) {
     mapped_size_ = bytes;
     DCHECK_EQ(0U, reinterpret_cast<uintptr_t>(memory_) &
-        (SharedMemory::MAP_MINIMUM_ALIGNMENT - 1));
+                      (SharedMemory::MAP_MINIMUM_ALIGNMENT - 1));
+    if (!SharedMemoryTracker::GetInstance()->IncrementMemoryUsage(*this))
+      return false;
   } else {
     memory_ = NULL;
   }
@@ -297,6 +300,7 @@ bool SharedMemory::Unmap() {
     return false;
 
   munmap(memory_, mapped_size_);
+  SharedMemoryTracker::GetInstance()->DecrementMemoryUsage(*this);
   memory_ = NULL;
   mapped_size_ = 0;
   return true;
@@ -318,6 +322,7 @@ void SharedMemory::Close() {
   if (mapped_file_ > 0) {
     if (IGNORE_EINTR(close(mapped_file_)) < 0)
       PLOG(ERROR) << "close";
+    SharedMemoryTracker::GetInstance()->DecrementMemoryUsage(*this);
     mapped_file_ = -1;
   }
   if (readonly_mapped_file_ > 0) {