[Fixed Position] Initially implement handles

Initially implement handles for resizing elements in a fixed
position view, WTD-882.

platform/features/layout/test/elements/ResizeHandleSpec.js

@@ -0,0 +1,59 @@
+/*global define,describe,it,expect,beforeEach,jasmine,xit*/
+
+define(
+    ['../../src/elements/ResizeHandle'],
+    function (ResizeHandle) {
+        "use strict";
+
+        var TEST_MIN_WIDTH = 4, TEST_MIN_HEIGHT = 2;
+
+        describe("A fixed position drag handle", function () {
+            var testElement,
+                handle;
+
+            beforeEach(function () {
+                testElement = {
+                    x: 3,
+                    y: 42,
+                    width: 30,
+                    height: 36
+                };
+
+                handle = new ResizeHandle(
+                    testElement,
+                    TEST_MIN_WIDTH,
+                    TEST_MIN_HEIGHT
+                );
+            });
+
+            it("provides x/y grid coordinates for lower-right corner", function () {
+                expect(handle.x()).toEqual(33);
+                expect(handle.y()).toEqual(78);
+            });
+
+            it("changes width of an element", function () {
+                handle.x(30);
+                // Should change width, not x
+                expect(testElement.x).toEqual(3);
+                expect(testElement.width).toEqual(27);
+            });
+
+            it("changes height of an element", function () {
+                handle.y(60);
+                // Should change height, not y
+                expect(testElement.y).toEqual(42);
+                expect(testElement.height).toEqual(18);
+            });
+
+            it("enforces minimum width/height", function () {
+                handle.x(testElement.x);
+                handle.y(testElement.y);
+                expect(testElement.x).toEqual(3);
+                expect(testElement.y).toEqual(42);
+                expect(testElement.width).toEqual(TEST_MIN_WIDTH);
+                expect(testElement.height).toEqual(TEST_MIN_HEIGHT);
+            });
+
+        });
+    }
+);