Leak reports collect information about the memory usage

chrome/browser/metrics/leak_detector/leak_detector_controller_unittest.cc

 // 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.
 
 #include "chrome/browser/metrics/leak_detector/leak_detector_controller.h"
 
 #include <set>
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
@@ skipping 14 matching lines @@
   *output = ::google::protobuf::RepeatedField<T>(input.begin(), input.end());
 }
 
 }  // namespace
 
 // Test class for LeakDetectorController that exposes protected methods.
 class TestLeakDetectorController : public LeakDetectorController {
  public:
   using LeakDetectorController::OnLeaksFound;
 
-  TestLeakDetectorController() {}
+  // This constructor suppresses starting memory metrics job in the superclass.
+  TestLeakDetectorController() {
+    LeakDetectorController::waiting_for_collect_memory_usage_ = true;

[Simon Que, 2016/10/07 06:24:58]

You have the right idea but this is not the best design pattern. This is a state
variable that you're treating like an initialization flag.

Instead, create a separate boolean in LeakDetectorController to indicate whether
memory usage info should be collected. Initialize that to true by default, and
then set it to false here.

[mwlodar, 2016/10/07 18:54:35]

Done.

+  }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestLeakDetectorController);
 };
 
 class LeakDetectorControllerTest : public ::testing::Test {
  public:
   LeakDetectorControllerTest() {}
 
  private:
@@ skipping 211 matching lines @@
   EXPECT_EQ(13U, stored_reports[2].call_stack().Get(4));
   EXPECT_EQ(14U, stored_reports[2].call_stack().Get(5));
   EXPECT_EQ(15U, stored_reports[2].call_stack().Get(6));
   EXPECT_EQ(16U, stored_reports[2].call_stack().Get(7));
 
   controller->GetLeakReports(&stored_reports);
   ASSERT_EQ(0U, stored_reports.size());
 }
 
 }  // namespace metrics