Mojo interface/service for Leak Detector on remote process

components/metrics/leak_detector/leak_detector_remote.mojom

+// 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.
+
+module metrics;
+
+struct LeakDetectorParams {
+  float sampling_rate;
+  uint32 max_stack_depth;
+  uint64 analysis_interval_bytes;
+  uint32 size_suspicion_threshold;
+  uint32 call_stack_suspicion_threshold;
+};
+
+struct AllocationBreakdown {
+  array<uint32> counts_by_size;
+  uint32 count_for_call_stack;
+};
+
+struct MemoryLeakReport {
+  uint32 size_bytes;
+  array<uint64> call_stack;
+
+  enum ProcessType {
+    UNKNOWN_PROCESS = 0,
+    BROWSER_PROCESS = 1,
+    RENDERER_PROCESS = 2,
+  };
+  ProcessType process_type;
+
+  array<AllocationBreakdown> alloc_breakdown_history;
+};
+
+// Provides a remote interface for enabling LeakDetector on remote processes.
+interface LeakDetectorRemote {

[Ben Goodger (Google), 2016/06/17 22:22:03]

Can we not use the *Remote suffix for something that might be in another
process? Most mojom interfaces are implemented in remote processes & we don't
use this convention for then.

[Simon Que, 2016/06/18 04:17:53]

I can't use "LeakDetector" because that name already exists in the metrics
namespace.

How about "LeakDetectorInterface"?

[dcheng, 2016/06/18 06:17:08]

The general convention is to define mojo interfaces in a nested mojom namespace,
which prevents this collision. For an example, look at //url/mojo (which also
had examples of unit testing).

+  // Returns a LeakDetectorParams struct. Used to indicate to the remote process
+  // what parameters to use when initializing LeakDetector. Can also return
+  // |params.sampling_rate| == 0 to indicate that LeakDetector should not be
+  // initialized on a particular process.
+  GetParams() => (LeakDetectorParams params);
+
+  // When a remote process running LeakDetector gets some leak reports, it
+  // should call this function to return the leak reports back to the main
+  // process that implements this function. The reports should be sent back as
+  // an array of serialized MemoryLeakReportProtos.
+  SendLeakReports(array<MemoryLeakReport> reports);
+};