On heap tracking datastructure overflow, degrade instead of CHECK()

base/trace_event/heap_profiler_allocation_register.cc

Index: base/trace_event/heap_profiler_allocation_register.cc
diff --git a/base/trace_event/heap_profiler_allocation_register.cc b/base/trace_event/heap_profiler_allocation_register.cc
index 63d40611a6f6dcef24d2f524ff60ebf1994dfe62..f9868ea7a803b8aec24b78f16c99707a3c172970 100644
--- a/base/trace_event/heap_profiler_allocation_register.cc
+++ b/base/trace_event/heap_profiler_allocation_register.cc
@@ -81,12 +81,12 @@ AllocationRegister::AllocationRegister(size_t allocation_capacity,
 AllocationRegister::~AllocationRegister() {
 }
 
-void AllocationRegister::Insert(const void* address,
+bool AllocationRegister::Insert(const void* address,
                                 size_t size,
                                 const AllocationContext& context) {
   DCHECK(address != nullptr);
   if (size == 0) {
-    return;
+    return false;
   }
 
   AllocationInfo info = {
@@ -97,12 +97,15 @@ void AllocationRegister::Insert(const void* address,
 
   // Try to insert the allocation.
   auto index_and_flag = allocations_.Insert(address, info);
-  if (!index_and_flag.second) {
+  if (!index_and_flag.second &&
+      index_and_flag.first != AllocationMap::kInvalidKVIndex) {
     // |address| is already there - overwrite the allocation info.
     auto& old_info = allocations_.Get(index_and_flag.first).second;
     RemoveBacktrace(old_info.backtrace_index);
     old_info = info;
   }

[Primiano Tucci (use gerrit), 2017/03/31 19:05:47]

minor thing, but  this branch should return true, as the insert technically
succeeded here (by replacing the old entry).

+
+  return index_and_flag.second;
 }
 
 void AllocationRegister::Remove(const void* address) {
@@ -149,8 +152,10 @@ void AllocationRegister::EstimateTraceMemoryOverhead(
 AllocationRegister::BacktraceMap::KVIndex AllocationRegister::InsertBacktrace(
     const Backtrace& backtrace) {
   auto index = backtraces_.Insert(backtrace, 0).first;
-  auto& backtrace_and_count = backtraces_.Get(index);
-  backtrace_and_count.second++;
+  if (index != BacktraceMap::kInvalidKVIndex) {
+    auto& backtrace_and_count = backtraces_.Get(index);
+    backtrace_and_count.second++;
+  }
   return index;
 }