Add CSS support for text-decoration-skip

third_party/WebKit/LayoutTests/fast/css3-text/css3-text-decoration/resources/text-decoration-skip-css-support.js

+var validWriteExpectations = ['ink',
+                               'objects',
+                               'objects ink'];
+
+var writeInvalidExpectations = ['none objects', // Combinations with none invalid
+                                'none', // none currently not supported
+                                'abc def',
+                                '',
+                                'objects objects',
+                                'ink ink',
+                                'edges'] // not supported yet
+
+setup({ explicit_done: true });
+
+function styleAndComputedStyleReadback() {
+
+    var testContainer = document.createElement("div");
+    document.body.appendChild(testContainer);
+
+    for (validValue of validWriteExpectations) {
+        testContainer.style.textDecorationSkip = validValue;
+        test(function() {
+            assert_equals(testContainer.style.textDecorationSkip, validValue);
+            assert_equals(getComputedStyle(testContainer).textDecorationSkip, validValue);
+        }, 'text-decoration-skip value ' + validValue + ' should be equal when reading it back from style and getComputedstyle.');
+    }
+
+    document.body.removeChild(testContainer);
+}
+
+function testInheritance() {
+    var testContainer = document.createElement('div');
+    var testContainerChild = document.createElement('div');
+    testContainer.appendChild(testContainerChild);
+    document.body.appendChild(testContainer);
+
+    for (validValue of validWriteExpectations) {
+        testContainer.style.textDecorationSkip = validValue;
+        test(function() {
+            assert_equals(testContainerChild.style.textDecorationSkip, '');
+            assert_equals(getComputedStyle(testContainerChild).textDecorationSkip, validValue);
+        }, 'text-decoration-skip value ' + validValue + ' should be inherited to computed style of child.');
+    }
+    document.body.removeChild(testContainer);
+}
+
+function validWriteTests() {
+    for (validValue of validWriteExpectations) {
+        test(function() {
+            assert_true(CSS.supports('text-decoration-skip', validValue));
+        }, 'Value ' + validValue + ' valid for property text-decoration-skip');
+    }
+}
+
+function invalidWriteTests() {
+    for (invalidValue of writeInvalidExpectations) {
+        test(function() {
+            assert_false(CSS.supports('text-decoration-skip', invalidValue));
+        }, 'Value ' + invalidValue + ' invalid for property text-decoration-skip');
+    }
+}
+
+window.addEventListener('load', function() {
+    validWriteTests();
+    invalidWriteTests();
+    styleAndComputedStyleReadback();
+    testInheritance();
+    done();
+});