Add some plumbing for the color management of canvases

third_party/WebKit/Source/core/html/canvas/CanvasContextCreationAttributes.idl

 // Copyright 2014 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.
 
 // The spec for HTMLCanvasElement.getContext() defines the context
 // creation attributes as type "any". In order to eliminate custom
 // bindings for getContext(), we define a dictionary that contains the
 // union of all of the context types' attributes. Note that it is not
 // possible to use a union type for this purpose because two dictionary
 // types are not distinguishable.
 //
 // Fortunately, there aren't any context creation attributes which are
 // defined with different default values in different context
 // specifications. (The "alpha" value, in particular, has a default
 // value of true for both the Canvas2D and WebGL specifications.)
 //
 // The PermissiveDictionaryConversion extended attribute ignores
 // non-object types (like 'true' and 'false') passed to getContext() for
 // the attributes instead of raising TypeError, following the behavior
 // of the previous custom binding.
 //
 // N.B.: Web IDL doesn't support multiple inheritance of dictionaries.
 
 [PermissiveDictionaryConversion]
 dictionary CanvasContextCreationAttributes {
     // Canvas 2D attributes
     boolean alpha = true;  // Also used for WebGL.
+    [RuntimeEnabled=ExperimentalCanvasFeatures] DOMString colorSpace = "legacy-srgb";
 
     // WebGL attributes
     boolean depth = true;
     boolean stencil = false;
     boolean antialias = true;
     boolean premultipliedAlpha = true;
     boolean preserveDrawingBuffer = false;
     boolean failIfMajorPerformanceCaveat = false;
 };