[tracing] Expose memory-infra tracing infrastructure to Blink.

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 65 matching lines @@
 class WebFileUtilities;
 class WebFlingAnimator;
 class WebGeofencingProvider;
 class WebGestureCurve;
 class WebGraphicsContext3DProvider;
 class WebIDBFactory;
 class WebMIDIAccessor;
 class WebMIDIAccessorClient;
 class WebMediaStreamCenter;
 class WebMediaStreamCenterClient;
+class WebMemoryDumpProvider;
 class WebMessagePortChannel;
 class WebMimeRegistry;
 class WebNavigatorConnectProvider;
 class WebNotificationManager;
 class WebPermissionClient;
 class WebPluginListBuilder;
 class WebPrescientNetworking;
 class WebPublicSuffixList;
 class WebPushProvider;
 class WebRTCPeerConnectionHandler;
@@ skipping 453 matching lines @@
     // Enumeration histogram buckets are linear, boundaryValue should be larger than any possible sample value.
     virtual void histogramEnumeration(const char* name, int sample, int boundaryValue) { }
     // Unlike enumeration histograms, sparse histograms only allocate memory for non-empty buckets.
     virtual void histogramSparse(const char* name, int sample) { }
 
     // Record to a RAPPOR privacy-preserving metric, see: https://www.chromium.org/developers/design-documents/rappor.
     // recordRappor records a sample string, while recordRapporURL records the domain and registry of a url.
     virtual void recordRappor(const char* metric, const WebString& sample) { }
     virtual void recordRapporURL(const char* metric, const blink::WebURL& url) { }
 
+    // Registers a memory dump provider. The WebMemoryDumpProvider::onMemoryDump
+    // method will be called on the same thread that called the
+    // registerMemoryDumpProvider() method.
+    // See crbug.com/458295 for design docs.
+    virtual void registerMemoryDumpProvider(blink::WebMemoryDumpProvider*) { }
+
+    // Must be called on the thread that called registerMemoryDumpProvider().
+    virtual void unregisterMemoryDumpProvider(blink::WebMemoryDumpProvider*) { }
+
     // GPU ----------------------------------------------------------------
     //
     // May return null if GPU is not supported.
     // Returns newly allocated and initialized offscreen WebGraphicsContext3D instance.
     // Passing an existing context to shareContext will create the new context in the same share group as the passed context.
     virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&, WebGraphicsContext3D* shareContext) { return 0; }
     virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&, WebGraphicsContext3D* shareContext, WebGLInfo* glInfo) { return 0; }
     virtual WebGraphicsContext3D* createOffscreenGraphicsContext3D(const WebGraphicsContext3D::Attributes&) { return 0; }
 
     // Returns a newly allocated and initialized offscreen context provider. The provider may return a null
@@ skipping 115 matching lines @@
 protected:
     BLINK_PLATFORM_EXPORT Platform();
     virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };
 
 } // namespace blink
 
 #endif