Second reland: Introduce mojo interface for collecting StackSamplingProfiler data

components/metrics/public/interfaces/BUILD.gn

+# 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.
+
+import("//mojo/public/tools/bindings/mojom.gni")
+
+mojom("call_stack_mojo_bindings") {
+  sources = [
+    "call_stack_profile_collector.mojom",
+  ]
+
+  deps = [
+    "//mojo/common:common_custom_types",
+  ]
+}
+
+mojom("call_stack_mojo_test_bindings") {
+  sources = [
+    "call_stack_profile_collector_test.mojom",
+  ]
+
+  deps = [
+    ":call_stack_mojo_bindings",
+    "//mojo/common:common_custom_types",
+  ]
+}