Store alloc history data in memory leak report protobuf

components/metrics/leak_detector/leak_detector.h

Index: components/metrics/leak_detector/leak_detector.h
diff --git a/components/metrics/leak_detector/leak_detector.h b/components/metrics/leak_detector/leak_detector.h
index 319e38695949e7a2137d76ecd802cc22a740f61b..3e49888d807fd0ab4d8fd56fdb2c04b755e21003 100644
--- a/components/metrics/leak_detector/leak_detector.h
+++ b/components/metrics/leak_detector/leak_detector.h
@@ -49,7 +49,21 @@ class LeakDetectorImpl;
 class LeakDetector {
  public:
   // Contains a report of a detected memory leak.
+  // TODO(sque): This is becoming a copy of LeakDetectorImpl::LeakReport. Need
+  // to merge the two.

[Simon Que, 2016/04/11 20:31:25]

I wonder if LeakDetector should just create a protobuf here and use MergeFrom()
in LeakDetectorController to merge with the template.

[Ilya Sherman, 2016/04/13 00:07:12]

Yeah, that seems pretty reasonable.

[Simon Que, 2016/04/13 22:41:31]

Done.

   struct LeakReport {
+    // This is a copy of LeakDetectorImpl::LeakReport::AllocationBreakdown. The
+    // only difference is that it uses a plain std::vector instead of an
+    // InternalVector (custom std::vector). See the definition of that struct
+    // for more information.
+    struct AllocationBreakdown {
+      AllocationBreakdown();
+      ~AllocationBreakdown();
+
+      std::vector<uint32_t> counts_by_size;
+      uint32_t count_for_call_stack;
+    };
+
     LeakReport();
     ~LeakReport();
 
@@ -58,6 +72,9 @@ class LeakDetector {
     // Unlike the CallStack struct, which consists of addresses, this call stack
     // will contain offsets in the executable binary.
     std::vector<uintptr_t> call_stack;
+
+    // Historical records of allocation data.
+    std::vector<AllocationBreakdown> alloc_breakdown_history;

[Ilya Sherman, 2016/04/13 00:07:12]

Optional nit: Mebbe s/alloc/allocation, given the type name?

[Simon Que, 2016/04/13 22:41:31]

The corresponding field in the protobuf is "alloc_breakdown_history" so I
decided to match that.

   };
 
   // Interface for receiving leak reports.