Add LeakDetectorRemoteController as a Mojo service

chrome/browser/metrics/leak_detector_remote_controller.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 CHROME_BROWSER_METRICS_LEAK_DETECTOR_REMOTE_CONTROLLER_H_
+#define CHROME_BROWSER_METRICS_LEAK_DETECTOR_REMOTE_CONTROLLER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "components/metrics/leak_detector/leak_detector_remote.mojom.h"
+#include "components/metrics/proto/memory_leak_report.pb.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+
+namespace metrics {
+
+// This class acts as an interface to LeakDetector clients running on processes
+// other than its own (the browser process).
+class LeakDetectorRemoteController : public LeakDetectorRemote {
+ public:
+  // Interface class to be implemented by a local controller class that provides
+  // leak detector parameters and can pass leak reports to UMA.
+  class LocalController {
+   public:
+    // Returns a set of leak detection params to be used when initializing the
+    // leak detector on a remote process.
+    virtual void GetParams(MemoryLeakReportProto_Params* params) const = 0;

[Ilya Sherman, 2016/06/07 23:03:38]

Why does this function fill a pointer, rather than returning a value (either by
copy or by const reference)?

[Simon Que, 2016/06/08 01:14:18]

Done.

+
+    // Pass a vector of memory leak reports provided by a remote process to the
+    // local controller class.
+    virtual void SendLeakReports(
+        const std::vector<MemoryLeakReportProto>& reports) = 0;
+  };
+
+  ~LeakDetectorRemoteController() override;
+
+  static void Create(LeakDetectorRemoteRequest request);
+
+  // LeakDetectorRemote

[Ilya Sherman, 2016/06/07 23:03:38]

nit: Please add a trailing colon, ':'

[Simon Que, 2016/06/08 01:14:18]

Done.

+  void GetParams(const LeakDetectorRemote::GetParamsCallback& cb) override;
+
+  // LeakDetectorRemote

[Ilya Sherman, 2016/06/07 23:03:38]

nit: Please remove this line and the one above (lines 43-44)

[Simon Que, 2016/06/08 01:14:18]

Done.

+  void SendLeakReports(mojo::Array<mojo::String>) override;
+
+  static void SetLocalControllerInstance(LocalController* controller) {

[Ilya Sherman, 2016/06/07 23:03:38]

nit: Please use hacker_case

[Simon Que, 2016/06/08 01:14:18]

Done.

+    controller_ = controller;
+  }
+
+ private:
+  explicit LeakDetectorRemoteController(LeakDetectorRemoteRequest request);
+
+  // Single instance of LocalController. All remote LeakDetector clients will
+  // get their params from and send leak reports to this instance.
+  static LocalController* controller_;

[Ilya Sherman, 2016/06/07 23:03:38]

Optional nit: I think it's slightly preferable to have a global pointer defined
in the anonymous namespace in the implementation file.  It's effectively
equivalent, but a bit clearer about what is happening.

[Simon Que, 2016/06/08 01:14:18]

Done.

+
+  mojo::StrongBinding<metrics::LeakDetectorRemote> binding_;
+
+  DISALLOW_COPY_AND_ASSIGN(LeakDetectorRemoteController);
+};
+
+}  // namespace metrics
+
+#endif  // CHROME_BROWSER_METRICS_LEAK_DETECTOR_REMOTE_CONTROLLER_H_