Convert RuntimeEnabledFeatures.in config file to JSON format.

third_party/WebKit/Source/bindings/IDLExtendedAttributes.md

 # Blink IDL Extended Attributes
 
 [TOC]
 
 ## Introduction
 
 The main interest in extended attributes are their _semantics_: Blink implements many more extended attributes than the Web IDL standard, to specify various behavior.
 
 The authoritative list of allowed extended attributes and values is [bindings/IDLExtendedAttributes.txt](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/bindings/IDLExtendedAttributes.txt). This is complete but not necessarily precise (there may be unused extended attributes or values), since validation is run on build, but coverage isn't checked.
 
@@ skipping 1005 matching lines @@
 [NotEnumerable] attribute DOMString str;
 [NotEnumerable] void foo();
 ```
 
 `[NotEnumerable]` indicates that the method or attribute is not enumerable.
 
 ### [OriginTrialEnabled] _(i, m, a, c)_
 
 Summary: Like `[RuntimeEnabled]`, it controls at runtime whether bindings are exposed, but uses a different mechanism for enabling experimental features.
 
-Usage: `[OriginTrialEnabled=FeatureName]`. FeatureName must be included in [RuntimeEnabledFeatures.in](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in), and is the same value that would be used with `[RuntimeEnabled]`.
+Usage: `[OriginTrialEnabled=FeatureName]`. FeatureName must be included in [RuntimeEnabledFeatures.json5](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5), and is the same value that would be used with `[RuntimeEnabled]`.
 
 ```webidl
 [
     OriginTrialEnabled=MediaSession
 ] interface MediaSession { ... };
 ```
 
 When there is an active origin trial for the current execution context, the feature is enabled at runtime, and the binding would be exposed to the web. `[OriginTrialEnabled]` also includes a check for the associated runtime flag, so features can be enabled in that fashion, even without an origin trial.
 
 `[OriginTrialEnabled]` has similar semantics to `[RuntimeEnabled]`, and is intended as a drop-in replacement. For example, `[OriginTrialEnabled]` _cannot_ be applied to arguments, see `[RuntimeEnabled]` for reasoning. The key implementation difference is that `[OriginTrialEnabled]` wraps the generated code with `if (OriginTrials::FeatureNameEnabled(...)) { ...code... }`.
 
-For more information, see [RuntimeEnabledFeatures](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in) and [OriginTrialContext](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/core/origin_trials/OriginTrialContext.h).
+For more information, see [RuntimeEnabledFeatures](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5) and [OriginTrialContext](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/core/origin_trials/OriginTrialContext.h).
 
 *** note
 **FIXME:** Currently, `[OriginTrialEnabled]` can only be applied to interfaces, attributes, and constants. Methods (including those generated by `iterable`, `setlike`, `maplike`, `serializer` and `stringifier`) are not supported. See [Bug 621641](https://crbug.com/621641).
 ***
 
 ### [PostMessage] _(m)_
 
 Summary: Tells the code generator to generate postMessage method used in Workers, Service Workers etc.
 
 Usage: `[PostMessage]` can be specified on methods
@@ skipping 174 matching lines @@
 The ReflectOnly attribute limits the range of values that the attribute getter can return from its reflected attribute. If the content attribute has a value that is a case-insensitive match for one of the values given in the `ReflectOnly`'s list (using "`|`" as separator), then it will be returned. To allow attribute values that use characters that go beyond what IDL identifiers may contain, string literals are used. This is a Blink syntactic extension to extended attributes.
 
 If there is no match, the empty string will be returned. As required by the specification, no such checking is performed when the reflected IDL attribute is set.
 
 `[ReflectOnly=<list>]` should be used if the specification for a reflected IDL attribute says it is _"limited to only known values"_.
 
 ### [RuntimeEnabled] _(i, m, a, c)_
 
 Summary: `[RuntimeEnabled]` wraps the generated code with `if (RuntimeEnabledFeatures::FeatureNameEnabled) { ...code... }`.
 
-Usage: `[RuntimeEnabled=FeatureName]`. FeatureName must be included in [RuntimeEnabledFeatures.in](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in).
+Usage: `[RuntimeEnabled=FeatureName]`. FeatureName must be included in [RuntimeEnabledFeatures.in](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5).
 
 ```webidl
 [
     RuntimeEnabled=MediaSession
 ] interface MediaSession { ... };
 ```
 
 Only when the feature is enabled at runtime (using a command line flag, for example, or when it is enabled only in certain platforms), the binding would be exposed to the web.
 
 `[RuntimeEnabled]` _cannot_ be applied to arguments, as this changes signatures and method resolution and is both very confusing to reason about and implement. For example, what does it mean to mark a _required_ argument as `[RuntimeEnabled]`? You probably want to apply it only to optional arguments, which are equivalent to overloads. Thus instead apply `[RuntimeEnabled]` to the _method_, generally splitting a method in two. For example, instead of:
 
 ```webidl
 foo(long x, `[RuntimeEnabled=FeatureName]` optional long y); // Don't do this!
 ```
 
 do:
 
 ```webidl
 // Overload can be replaced with optional if `[RuntimeEnabled]` is removed
 foo(long x);
 [RuntimeEnabled=FeatureName] foo(long x, long y);
 ```
 
-For more information, see [RuntimeEnabledFeatures](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in).
+For more information, see [RuntimeEnabledFeatures](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5).
 
 ### [SaveSameObject] _(a)_
 
 Summary: Caches the resulting object and always returns the same object.
 
 When specified, caches the resulting object and returns it in later calls so that the attribute always returns the same object. Must be accompanied with `[SameObject]`.
 
 ## Rare Blink-specific IDL Extended Attributes
 
 These extended attributes are rarely used, generally only in one or two places. These are often replacements for `[Custom]` bindings, and may be candidates for deprecation and removal.
@@ skipping 337 matching lines @@
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 
 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 
 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
 
 THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ***
 
 [CrossOriginProperties]: https://html.spec.whatwg.org/multipage/browsers.html#crossoriginproperties-(-o-)