Adding v8_isolate_memory_dump_provider.

gin/v8_isolate_memory_dump_provider.h

+// Copyright 2015 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 GIN_V8_ISOLATE_MEMORY_DUMP_PROVIDER_H_
+#define GIN_V8_ISOLATE_MEMORY_DUMP_PROVIDER_H_
+
+#include "base/trace_event/memory_dump_provider.h"
+#include "gin/gin_export.h"
+
+namespace gin {
+
+class IsolateHolder;
+
+// Memory dump provider for the chrome://tracing infrastructure. It dumps
+// summarized memory stats about the V8 Isolates.
+class V8IsolateMemoryDumpProvider
+    : public base::trace_event::MemoryDumpProvider {
+ public:
+  V8IsolateMemoryDumpProvider(IsolateHolder* isolate_holder);

[Primiano Tucci (use gerrit), 2015/04/21 16:43:42]

When you have a ctor with one argument, you want "explicit V8IsolateMDP(....)",
otherwise C++ will derive an implicit cast operator between IsolateHolder and
V8IsolateMDP, which you don't really want.

[ssid, 2015/04/21 17:38:23]

Done.

+  ~V8IsolateMemoryDumpProvider() override;
+
+  // MemoryDumpProvider implementation.
+  bool DumpInto(base::trace_event::ProcessMemoryDump* pmd) override;
+  const char* GetFriendlyName() const override;
+
+ private:
+  IsolateHolder* isolate_holder_;  // Not owned.

[Primiano Tucci (use gerrit), 2015/04/21 16:43:43]

maybe say:

// Not owned (IsolateHolder owns this)

[ssid, 2015/04/21 17:38:23]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(V8IsolateMemoryDumpProvider);
+};
+
+}  // namespace gin
+
+#endif  // GIN_V8_ISOLATE_MEMORY_DUMP_PROVIDER_H_