Adding blink gc memory dump infrastructure for thread specific dumps.

Source/platform/heap/BlinkGCMemoryDumpProvider.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 BlinkGCMemoryDumpProvider_h
 #define BlinkGCMemoryDumpProvider_h
 
 #include "platform/PlatformExport.h"
+#include "platform/TraceEvent.h"

[Primiano Tucci (use gerrit), 2015/05/27 14:19:30]

do you really need this or is just a leftover from the previous patchsets?

[ssid, 2015/05/27 14:39:33]

Forgot to upload the last patch.

 #include "public/platform/WebMemoryDumpProvider.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/text/WTFString.h"
 
 namespace blink {
+class WebMemoryAllocatorDump;
 
 class PLATFORM_EXPORT BlinkGCMemoryDumpProvider final : public WebMemoryDumpProvider {
 public:
     static BlinkGCMemoryDumpProvider* instance();
     ~BlinkGCMemoryDumpProvider() override;
 
     // WebMemoryDumpProvider implementation.
     bool onMemoryDump(WebProcessMemoryDump*) override;
 
+    WebMemoryAllocatorDump* createMemoryAllocatorDumpForCurrentGC(const String& absoluteName);

[Primiano Tucci (use gerrit), 2015/05/27 14:19:31]

Can you add a comment clarifying that:
- the returned WebMemoryAllocatorDump is owned by BlinkGCMemoryDumpProvider
- the returned pointer should not be retained (just used to dump in the current
call stack).

[ssid, 2015/05/27 14:39:33]

Done.

+
 private:
     BlinkGCMemoryDumpProvider();
+
+    OwnPtr<WebProcessMemoryDump> m_currentProcessMemoryDump;
 };
 
 } // namespace blink
 
 #endif