Add versions of stroke, fill, and clip that take a Path parameter.

LayoutTests/fast/canvas/script-tests/canvas-path-context-clip.js

+description("Series of tests to ensure clip() works with path and winding rule parameters.");
+
+var ctx = document.getElementById('canvas').getContext('2d');
+
+function pixelDataAtPoint() {
+  return ctx.getImageData(50, 50, 1, 1).data;
+}
+
+function checkResult(expectedColors, sigma) {
+    for (var i = 0; i < 4; i++)
+      shouldBeCloseTo("pixelDataAtPoint()[" + i + "]", expectedColors[i], sigma);
+}
+
+function drawRectanglesOn(contextOrPath) {
+  contextOrPath.rect(0, 0, 100, 100);
+  contextOrPath.rect(25, 25, 50, 50);
+}
+
+function formatName(fillRule, path) {
+  return 'clip(' + (path ? 'path' : '') + (fillRule && path ? ', ' : '') +
+          (fillRule ? '"' + fillRule + '"' : '') + ')';
+}
+
+function testClipWith(fillRule, path) {
+    debug('Testing ' + formatName(fillRule, path));
+    ctx.fillStyle = 'rgb(255,0,0)';
+    ctx.beginPath();
+    ctx.fillRect(0, 0, 100, 100);
+    ctx.fillStyle = 'rgb(0,255,0)';
+    if (path) {
+      if (fillRule) {
+        ctx.clip(path, fillRule);
+      } else {
+        ctx.clip(path);
+      }
+    } else {
+      ctx.beginPath();
+      drawRectanglesOn(ctx);
+      if (fillRule) {
+        ctx.clip(fillRule);
+      } else {
+        ctx.clip();
+      }
+    }
+    ctx.beginPath();
+    ctx.fillRect(0, 0, 100, 100);
+    if (fillRule == 'evenodd') {
+      checkResult([255, 0, 0, 255], 5);
+    } else {
+      checkResult([0, 255, 0, 255], 5);
+    }
+    debug('');
+}
+
+// Execute test.
+function prepareTestScenario() {
+    fillRules = [undefined, 'nonzero', 'evenodd'];
+    var path = new Path();
+    drawRectanglesOn(path);
+
+    for (var i = 0; i < fillRules.length; i++) {
+       testClipWith(fillRules[i]);
+       testClipWith(fillRules[i], path);
+    }
+}
+
+// Run test and allow variation of results.
+prepareTestScenario();