memory coordinator: Add trace macros to track state changes

base/memory/memory_coordinator_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 "base/memory/memory_coordinator_client.h"
+
+#include "base/logging.h"

[haraken, 2016/11/01 04:20:29]

Do we need this?

[bashi, 2016/11/01 05:02:16]

NOTREACHED()

+
+namespace base {
+
+std::string MemoryStateToString(MemoryState state) {
+  switch (state) {
+    case MemoryState::UNKNOWN:
+      return "unknown";
+    case MemoryState::NORMAL:
+      return "normal";
+    case MemoryState::THROTTLED:
+      return "throttled";
+    case MemoryState::SUSPENDED:
+      return "suspended";
+    default:
+      NOTREACHED();
+  }
+}
+
+}  // namespace base
+

[haraken, 2016/11/01 04:20:29]

Unnecessary empty line.

[bashi, 2016/11/01 05:02:16]

Done.