Randomly enable leak detector based on probability parameter

chrome/renderer/leak_detector/leak_detector_remote_client.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/renderer/leak_detector/leak_detector_remote_client.h"
 
 #include "base/bind.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/metrics/leak_detector/protobuf_to_mojo_converter.h"
 #include "components/metrics/proto/memory_leak_report.pb.h"
@@ skipping 10 matching lines @@
   // |remote_service_|. See example at:
   // https://www.chromium.org/developers/design-documents/mojo/validation
   remote_service_->GetParams(base::Bind(
       &LeakDetectorRemoteClient::OnParamsReceived, base::Unretained(this)));
 }
 
 LeakDetectorRemoteClient::~LeakDetectorRemoteClient() {
   metrics::LeakDetector::GetInstance()->RemoveObserver(this);
 }
 
-void LeakDetectorRemoteClient::OnParamsReceived(
-    mojo::StructPtr<metrics::mojom::LeakDetectorParams> result) {
-  metrics::MemoryLeakReportProto::Params params;
-  metrics::leak_detector::protobuf_to_mojo_converter::MojoToParams(*result,
-                                                                   &params);
-
-  metrics::LeakDetector* detector = metrics::LeakDetector::GetInstance();
-  detector->AddObserver(this);
-  detector->Init(params, base::ThreadTaskRunnerHandle::Get());
-}
-
 void LeakDetectorRemoteClient::OnLeaksFound(
     const std::vector<metrics::MemoryLeakReportProto>& reports) {
   std::vector<mojo::StructPtr<metrics::mojom::MemoryLeakReport>> result;
 
   for (const metrics::MemoryLeakReportProto& report : reports) {
     metrics::mojom::MemoryLeakReportPtr mojo_report =
         metrics::mojom::MemoryLeakReport::New();
     metrics::leak_detector::protobuf_to_mojo_converter::ReportToMojo(
         report, mojo_report.get());
     result.push_back(std::move(mojo_report));
   }
 
   remote_service_->SendLeakReports(std::move(result));
 }
+
+void LeakDetectorRemoteClient::OnRenderProcessShutdown() {
+  remote_service_.reset();
+}
+
+void LeakDetectorRemoteClient::OnParamsReceived(
+    mojo::StructPtr<metrics::mojom::LeakDetectorParams> result) {
+  metrics::MemoryLeakReportProto::Params params;
+  metrics::leak_detector::protobuf_to_mojo_converter::MojoToParams(*result,
+                                                                   &params);
+
+  if (params.sampling_rate() > 0) {
+    metrics::LeakDetector* detector = metrics::LeakDetector::GetInstance();
+    detector->AddObserver(this);
+    detector->Init(params, base::ThreadTaskRunnerHandle::Get());
+  }
+}