[Fixed Position] Update specs

Update specs for Fixed Position view to ensure code coverage
after changes for resize/reposition behavior, WTD-882.

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

@@ -47,6 +47,13 @@ define(
                 proxy.order("top");
                 expect(testElements).toEqual([{}, {}, {}, testElement]);
             });
+
+            it("ensures x/y values are non-negative", function () {
+                proxy.x(-1);
+                proxy.y(-400);
+                expect(proxy.x()).toEqual(0);
+                expect(proxy.y()).toEqual(0);
+            });
         });
     }
 );

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

@@ -48,6 +48,7 @@ define(
                 expect(testElement.y).not.toEqual(testElement.y2);
             });
 
+
         });
     }
 );

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

@@ -67,6 +67,10 @@ define(
                 expect(proxy.y2()).toEqual(0);
             });
 
+            it("provides handles for both ends", function () {
+                expect(new LineProxy(diagonal).handles().length).toEqual(2);
+            });
+
         });
     }
 );