Add Custom Named property getters for cssStyleDeclaration to determine the existence of a property.

Source/bindings/dart/custom/DartCSSStyleDeclarationCustom.cpp

Index: Source/bindings/dart/custom/DartCSSStyleDeclarationCustom.cpp
diff --git a/Source/bindings/dart/custom/DartCSSStyleDeclarationCustom.cpp b/Source/bindings/dart/custom/DartCSSStyleDeclarationCustom.cpp
index 2e53a9167473e33d8a4fa6a3c2d4a2e47a4d92e9..9d76d15b49fc9890a8fa34e1152785c333d1ef71 100644
--- a/Source/bindings/dart/custom/DartCSSStyleDeclarationCustom.cpp
+++ b/Source/bindings/dart/custom/DartCSSStyleDeclarationCustom.cpp
@@ -30,8 +30,29 @@
 #include "config.h"
 #include "DartCSSStyleDeclaration.h"
 
+#include "CSSPropertyNames.h"
+#include "core/css/CSSPrimitiveValue.h"
+#include "core/css/CSSStyleDeclaration.h"
+#include "core/css/CSSValue.h"
+#include "core/css/RuntimeCSSEnabled.h"
+#include "core/css/parser/BisonCSSParser.h"
+#include "wtf/ASCIICType.h"
+#include "wtf/PassRefPtr.h"
+#include "wtf/RefPtr.h"
+#include "wtf/StdLibExtras.h"
+#include "wtf/Vector.h"
+#include "wtf/text/StringBuilder.h"
+#include "wtf/text/StringConcatenate.h"
+
+using namespace WTF;
+using namespace std;
+
 namespace WebCore {
 
+struct CSSPropertyInfo {
+    CSSPropertyID propID;
+};
+
 namespace DartCSSStyleDeclarationInternal {
 
 void __setter__Callback(Dart_NativeArguments)
@@ -40,6 +61,117 @@ void __setter__Callback(Dart_NativeArguments)
     DART_UNIMPLEMENTED();
 }
 
+static bool hasCSSPropertyNamePrefix(const String& propertyName, const char* prefix)
+{
+#ifndef NDEBUG
+    ASSERT(*prefix);
+    for (const char* p = prefix; *p; ++p)
+        ASSERT(isASCIILower(*p));
+    ASSERT(propertyName.length());
+#endif
+
+    if (toASCIILower(propertyName[0]) != prefix[0])
+        return false;
+
+    unsigned length = propertyName.length();
+    for (unsigned i = 1; i < length; ++i) {
+        if (!prefix[i])
+            return isASCIIUpper(propertyName[i]);
+        if (propertyName[i] != prefix[i])
+            return false;
+    }
+    return false;
+}
+
+static CSSPropertyID cssResolvedPropertyID(const String& propertyName)
+{
+    unsigned length = propertyName.length();
+    if (!length)
+        return CSSPropertyInvalid;
+
+    StringBuilder builder;
+    builder.reserveCapacity(length);
+
+    unsigned i = 0;
+    bool hasSeenDash = false;
+
+    if (hasCSSPropertyNamePrefix(propertyName, "css"))
+        i += 3;
+    else if (hasCSSPropertyNamePrefix(propertyName, "webkit"))
+        builder.append('-');
+    else if (isASCIIUpper(propertyName[0]))
+        return CSSPropertyInvalid;
+
+    bool hasSeenUpper = isASCIIUpper(propertyName[i]);
+
+    builder.append(toASCIILower(propertyName[i++]));
+
+    for (; i < length; ++i) {
+        UChar c = propertyName[i];
+        if (!isASCIIUpper(c)) {
+            if (c == '-')
+                hasSeenDash = true;
+            builder.append(c);
+        } else {
+            hasSeenUpper = true;
+            builder.append('-');
+            builder.append(toASCIILower(c));
+        }
+    }
+
+    // Reject names containing both dashes and upper-case characters, such as "border-rightColor".
+    if (hasSeenDash && hasSeenUpper)
+        return CSSPropertyInvalid;
+
+    String propName = builder.toString();
+    return cssPropertyID(propName);
+}
+
+// When getting properties on CSSStyleDeclarations, the name used from
+// Javascript and the actual name of the property are not the same, so
+// we have to do the following translation. The translation turns upper
+// case characters into lower case characters and inserts dashes to
+// separate words.
+//
+// Example: 'backgroundPositionY' -> 'background-position-y'
+//
+// Also, certain prefixes such as 'css-' are stripped.
+static CSSPropertyInfo* cssPropertyInfo(const String& propertyName)
+{
+    typedef HashMap<String, CSSPropertyInfo*> CSSPropertyInfoMap;
+    DEFINE_STATIC_LOCAL(CSSPropertyInfoMap, map, ());
+    CSSPropertyInfo* propInfo = map.get(propertyName);
+    if (!propInfo) {
+        propInfo = new CSSPropertyInfo();
+        propInfo->propID = cssResolvedPropertyID(propertyName);
+        map.add(propertyName, propInfo);
+    }
+    if (propInfo->propID && RuntimeCSSEnabled::isCSSPropertyEnabled(propInfo->propID))
+        return propInfo;
+    return 0;
+}
+
+void propertyQuery(Dart_NativeArguments args)
+{
+    Dart_Handle exception = 0;
+    {
+        DartStringAdapter propertyName = DartUtilities::dartToString(args, 1, exception);
+        if (exception)
+            goto fail;
+
+        // NOTE: cssPropertyInfo lookups incur several mallocs.
+        // Successful lookups have the same cost the first time, but are cached.
+        if (cssPropertyInfo(propertyName)) {
+            Dart_SetReturnValue(args, DartUtilities::boolToDart(true));
+            return;
+        }
+    }
+
+fail:
+    Dart_ThrowException(exception);
+    ASSERT_NOT_REACHED();
+}
+
 }
 
 }