[bindings] Implement an ExperimentEnabled IDL extended attribute.

third_party/WebKit/Source/core/experiments/Experiments.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 Experiments_h
 #define Experiments_h
 
 #include "core/CoreExport.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/ExecutionContext.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 // The Experimental Framework (EF) provides limited access to experimental APIs,
 // on a per-origin basis.  This class provides an interface to API implementers,
 // for checking if the experimental API should be enabled for the current
 // context.
 //
 // Experimental APIs are defined by string names, provided by the implementers.
 // The EF code does not maintain an enum or constant list for experiment names.
 // Instead, the EF validates the name provided by the API implementation against
 // any provided API keys.
 // TODO(chasej): Link to documentation, or provide more detail on keys, .etc
 class CORE_EXPORT Experiments {
 public:
     static bool isApiEnabled(ExecutionContext*, const String& apiName, String& errorMessage);
+    static bool isApiEnabledWithoutMessage(ExecutionContext*, const String& apiName);

[haraken, 2015/12/18 02:35:51]

I'd prefer:

- isAPIEnabled (two args version) calls isAPIEnabledInternal
- isAPIEnabled (three args version) calls isAPIEnabledInternal

[Daniel Nishi, 2015/12/18 05:11:42]

Done.

     // Creates a NotSupportedError exception with a message explaining to
     // external developers why the API is disabled and how to join API
     // experiments.
     static DOMException* createApiDisabledException(const String& apiName);
 
 private:
     explicit Experiments();
 };
 
 } // namespace blink
 
 #endif // Experiments_h