Add UMA for PurgeAndSuspend.

third_party/WebKit/public/web/WebMemoryStatistics.h

Index: third_party/WebKit/public/web/WebMemoryStatistics.h
diff --git a/third_party/WebKit/public/web/WebMemoryStatistics.h b/third_party/WebKit/public/web/WebMemoryStatistics.h
new file mode 100644
index 0000000000000000000000000000000000000000..034224cd9b8f2d4889bc9ae241f3791be963ecfa
--- /dev/null
+++ b/third_party/WebKit/public/web/WebMemoryStatistics.h
@@ -0,0 +1,24 @@
+// 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.
+
+#ifndef WebMemoryStatistics_h
+#define WebMemoryStatistics_h
+
+#include "public/platform/WebCommon.h"
+
+namespace blink {
+
+struct WebMemoryStatistics {
+  size_t partitionAllocTotalAllocatedBytes;
+  size_t blinkGCTotalAllocatedBytes;
+
+  WebMemoryStatistics()
+      : partitionAllocTotalAllocatedBytes(0), blinkGCTotalAllocatedBytes(0) {}
+
+  BLINK_EXPORT static WebMemoryStatistics Get();
+};
+
+}  // namespace blink
+
+#endif