Added CSSPropertyAPI and CSS padding properties which implement this API

third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h

Index: third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
diff --git a/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h b/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
new file mode 100644
index 0000000000000000000000000000000000000000..c62831cede846c31dd1aced8d363cb4f97ccd791
--- /dev/null
+++ b/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
@@ -0,0 +1,30 @@
+// Copyright 2016 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 CSSPropertyAPI_h
+#define CSSPropertyAPI_h
+
+#include "core/CSSPropertyNames.h"
+#include "core/css/CSSValue.h"
+#include "core/css/parser/CSSParserMode.h"
+#include "core/css/parser/CSSParserTokenRange.h"
+
+namespace blink {
+
+// An API for CSS properties which allows you to call functions on properties

[alancutter (OOO until 2018), 2016/11/30 23:46:54]

"Allows you to call property specific functions"

[aazzam, 2016/12/01 04:17:53]

done

+// from within the parser. If the function doesn't have to be implemented by all
+// properties, provide a default implementation below.

[alancutter (OOO until 2018), 2016/11/30 23:46:54]

The last sentence is questionable. It would be implicit if you stated that the
specific properties were subclasses of CSSPropertyAPI.

[aazzam, 2016/12/01 04:17:53]

done

+

[sashab, 2016/11/30 23:48:39]

Remove newline below

Try reword to express that we will use this API to represent ALL
property-specific logic inside the blink style engine, with the eventual goal of
having no property logic outside of these classes

Add more instructions for using it:
- make a class that inherits from this class and implements all the static
methods (see existing child classes as examples)
- add new methods and static variables here (with optional default
implementations) if you want them implemented for all properties AND update
getDescriptor GET_DESCRIPTOR etc

[aazzam, 2016/12/01 04:17:53]

done

+class CSSPropertyAPI {
+ public:
+  static const CSSPropertyID id;

[sashab, 2016/11/30 23:48:39]

// A unique ID for the property.
// TODO(aazzam): Remove this once all callsites have been removed.

[aazzam, 2016/12/01 04:17:53]

done

+
+  // Parses the CSS property and returns a CSS Value.

[sashab, 2016/11/30 23:48:39]

or null if it could not be parsed.

[aazzam, 2016/12/01 04:17:53]

done

+  static const CSSValue* parseSingleValue(CSSParserTokenRange&,
+                                          const CSSParserContext&);
+};
+
+}  // namespace blink
+
+#endif  // CSSPropertyAPI_h