[DoNotSubmit] Added peak_memory_size to accounting-allocator.

src/base/accounting-allocator.cc

Index: src/base/accounting-allocator.cc
diff --git a/src/base/accounting-allocator.cc b/src/base/accounting-allocator.cc
index 2269c60680c0e1d13b542ebbc9a56451382560b5..72a9deeb6553f4b0cd6705128b334422e4d8f795 100644
--- a/src/base/accounting-allocator.cc
+++ b/src/base/accounting-allocator.cc
@@ -15,18 +15,31 @@ namespace base {
 
 void* AccountingAllocator::Allocate(size_t bytes) {
   void* memory = malloc(bytes);
-  if (memory) NoBarrier_AtomicIncrement(&current_memory_usage_, bytes);
+  if (memory) {
+    LockGuard<Mutex> guard(&mutex_);
+    current_memory_usage_ += bytes;
+    if (peak_memory_usage_ < current_memory_usage_)
+      peak_memory_usage_ = current_memory_usage_;
+  }
   return memory;
 }
 
 void AccountingAllocator::Free(void* memory, size_t bytes) {
   free(memory);
-  NoBarrier_AtomicIncrement(&current_memory_usage_,
-                            -static_cast<AtomicWord>(bytes));
+  {
+    LockGuard<Mutex> guard(&mutex_);
+    current_memory_usage_ -= bytes;
+  }
 }
 
 size_t AccountingAllocator::GetCurrentMemoryUsage() const {
-  return NoBarrier_Load(&current_memory_usage_);
+  LockGuard<Mutex> guard(const_cast<Mutex*>(&mutex_));
+  return current_memory_usage_;
+}
+
+size_t AccountingAllocator::GetPeakMemoryUsage() const {
+  LockGuard<Mutex> guard(const_cast<Mutex*>(&mutex_));
+  return peak_memory_usage_;
 }
 
 }  // namespace base