[tracing] Add graphics memory dump provider for Android

components/tracing/graphics_memory_dump_provider_android.h

Index: components/tracing/graphics_memory_dump_provider_android.h
diff --git a/components/tracing/graphics_memory_dump_provider_android.h b/components/tracing/graphics_memory_dump_provider_android.h
new file mode 100644
index 0000000000000000000000000000000000000000..9c561b8e8666b6cb5e0f0bebcc16f85a0ea9872c
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+++ b/components/tracing/graphics_memory_dump_provider_android.h
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+// 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 COMPONENTS_TRACING_GRAPHICS_MEMORY_DUMP_PROVIDER_ANDROID_H_
+#define COMPONENTS_TRACING_GRAPHICS_MEMORY_DUMP_PROVIDER_ANDROID_H_
+
+#include <string>
+
+#include "base/containers/hash_tables.h"
+#include "base/memory/singleton.h"
+#include "base/trace_event/memory_dump_provider.h"
+#include "components/tracing/tracing_export.h"
+
+namespace tracing {
+
+// Dump provider which collects memory stats about graphics memory on Android.
+// This requires the presence of the memtrack_helper daemon, which must be
+// executed separetely via a (root) adb shell command. The dump provider will
+// fail (and hence disabled by the MemoryDumpManager) in absence of the helper.
+// See the design-doc https://goo.gl/4Y30p9 for more details.
+class TRACING_EXPORT GraphicsMemoryDumpProvider
+    : public base::trace_event::MemoryDumpProvider {
+ public:
+  static GraphicsMemoryDumpProvider* GetInstance();
+
+  // MemoryDumpProvider implementation.
+  bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
+                    base::trace_event::ProcessMemoryDump* pmd) override;
+
+ private:
+  friend struct base::DefaultSingletonTraits<GraphicsMemoryDumpProvider>;
+
+  GraphicsMemoryDumpProvider();
+  ~GraphicsMemoryDumpProvider() override;
+
+  // Stores key names coming from the memtrack helper in long-lived storage.
+  // This is to allow using cheap char* strings in tracing without copies.
+  base::hash_set<std::string> key_names_;
+
+  DISALLOW_COPY_AND_ASSIGN(GraphicsMemoryDumpProvider);
+};
+
+}  // namespace tracing
+
+#endif  // COMPONENTS_TRACING_GRAPHICS_MEMORY_DUMP_PROVIDER_ANDROID_H_