Add RAPPOR metric recording for Device{Orientation,Motion} in 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 552 matching lines @@
     // Set the duration field of a COMPLETE trace event.
     virtual void updateTraceEventDuration(const unsigned char* categoryEnabledFlag, const char* name, TraceEventHandle) { }
 
     // Callbacks for reporting histogram data.
     // CustomCounts histogram has exponential bucket sizes, so that min=1, max=1000000, bucketCount=50 would do.
     virtual void histogramCustomCounts(const char* name, int sample, int min, int max, int bucketCount) { }
     // 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 RAPPOR.
+
+    // Record to RAPPOR, see: https://www.chromium.org/developers/design-documents/rappor
+    // Records a sample string to a Rappor privacy-preserving metric.
     virtual void recordRappor(const char* metric, const WebString& sample) { }
+    // Records a domain and registry of a url to a Rappor privacy-preserving metric.

[Mike West, 2015/04/14 05:20:38]

Nit: These method-level comments seem somewhat self-explanatory from the method
signature. I'd suggest dropping them. Adding the URL to the top-level comment is
a good idea, though!

[timvolodine, 2015/04/14 10:24:22]

I've added these comments on suggestion of koji@ and asvitkine@, I think one of
the concerns was that recordRapporURL might give the wrong impression that we
are logging urls..

+    virtual void recordRapporURL(const char* metric, const blink::WebURL& url) { }
 
     // 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; }
 
@@ skipping 116 matching lines @@
 protected:
     BLINK_PLATFORM_EXPORT Platform();
     virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };
 
 } // namespace blink
 
 #endif