Handle zero-size allocations properly in heap profiler

base/trace_event/heap_profiler_allocation_register.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/trace_event/heap_profiler_allocation_register.h"
 
 #include "base/trace_event/trace_event_memory_overhead.h"
 
 namespace base {
 namespace trace_event {
@@ skipping 18 matching lines @@
 
 AllocationRegister::~AllocationRegister() {
   FreeVirtualMemory(buckets_, kNumBuckets * sizeof(CellIndex));
   FreeVirtualMemory(cells_, num_cells_ * sizeof(Cell));
 }
 
 void AllocationRegister::Insert(void* address,
                                 size_t size,
                                 AllocationContext context) {
   DCHECK(address != nullptr);
+  if (size == 0)
+    return;
 
   CellIndex* idx_ptr = Lookup(address);
 
   // If the index is 0, the address is not yet present, so insert it.
   if (*idx_ptr == 0) {
     *idx_ptr = GetFreeCell();
 
     // The address stored in a cell is const as long as it is exposed (via the
     // iterators or |Get|), but because cells are re-used, a const cast is
     // required to set it on insert and remove.
@@ skipping 139 matching lines @@
   size_t resident = sizeof(AllocationRegister)
                     // Include size of touched cells (size of |*cells_|).
                     + sizeof(Cell) * next_unused_cell_
                     // Size of |*buckets_|.
                     + sizeof(CellIndex) * kNumBuckets;
   overhead->Add("AllocationRegister", allocated, resident);
 }
 
 }  // namespace trace_event
 }  // namespace base