Store alloc history data in memory leak report protobuf

components/metrics/leak_detector/leak_detector.h

 // Copyright 2016 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.
 
 #ifndef COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_
 #define COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 31 matching lines @@
 // - AllocHook
 // - FreeHook
 // - AddObserver
 // - RemoveObserver
 //
 // All other functions must always be called from the same thread. This is
 // enforced with a DCHECK.
 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();
 
     size_t alloc_size_bytes;
 
     // 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.
   class Observer {
    public:
     virtual ~Observer() {}
 
     // Called by leak detector to report a leak.
     virtual void OnLeakFound(const LeakReport& report) = 0;
   };
@@ skipping 93 matching lines @@
   // corresponds to the allowable range of |sampling_rate| passed in during
   // initialization: [0.0f, 1.0f] -> [0, UINT64_MAX].
   uint64_t sampling_factor_;
 
   DISALLOW_COPY_AND_ASSIGN(LeakDetector);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_LEAK_DETECTOR_LEAK_DETECTOR_H_