Add CSS support for font-variation-settings

third_party/WebKit/LayoutTests/fast/css/resources/font-variation-settings-css-support.js

+var validWriteExpectations = [ "normal",
+                               "'abcd' 1",
+                               "'abcd' 0, 'efgh' 1",
+                               "'abcd' 0.3, 'efgh' 1.4",
+                               "'abcd' -1000, 'efgh' -10000",
+                               "'abcd' 0.3, 'abcd' 0.4, 'abcd' 0.5, 'abcd' 0.6, 'abcd' 0.7" ];
+
+var writeInvalidExpectations = ["none",
+                                "'abc' 1",
+                                "'abcde' 1",
+                                "",
+                                "'abc¡' 1",
+                                "normal, 'abcd' 0",
+                                "'abcd'",
+                                "'abcd' 1 2",
+                                "1 1",
+                                "0 0",
+                                "a a"];
+
+setup({ explicit_done: true });
+
+function styleAndComputedStyleReadback() {
+
+    var testContainer = document.createElement("div");
+    document.body.appendChild(testContainer);
+
+    for (validValue of validWriteExpectations) {
+        testContainer.style.fontVariationSettings = validValue;
+        test(function() {
+            assert_equals(testContainer.style.fontVariationSettings, validValue);
+            assert_equals(getComputedStyle(testContainer).fontVariationSettings, validValue);
+        }, 'font-variation-settings 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.fontVariationSettings = validValue;
+        test(function() {
+            assert_equals(testContainerChild.style.fontVariationSettings, '');
+            assert_equals(getComputedStyle(testContainerChild).fontVariationSettings, validValue);
+        }, 'font-variation-settings 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('font-variation-settings', validValue));
+        }, 'Value ' + validValue + ' valid for property font-variation-settings');
+    }
+}
+
+function invalidWriteTests() {
+    for (invalidValue of writeInvalidExpectations) {
+        test(function() {
+            assert_false(CSS.supports('font-variation-settings', invalidValue));
+        }, 'Value ' + invalidValue + ' invalid for property font-variation-settings');
+    }
+}
+
+window.addEventListener('load', function() {
+    validWriteTests();
+    invalidWriteTests();
+    styleAndComputedStyleReadback();
+    testInheritance();
+    done();
+});