Increase code coverage for RenderLayer::hitTestLayer.

Add tests for the NormalFlowChildren and transforms code paths.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/926823004

engine/core/rendering/RenderLayer.cpp

@@ -996,7 +996,6 @@ RenderLayer* RenderLayer::hitTestLayer(RenderLayer* rootLayer, RenderLayer* cont
     }
 
     // Now check our overflow objects.
-    // TODO(ojan): This call has no test coverage.
     hitLayer = hitTestChildren(NormalFlowChildren, rootLayer, request, result, hitTestRect, hitTestLocation,
                            localTransformState.get(), zOffsetForDescendantsPtr, zOffset, unflattenedTransformState.get(), depthSortDescendants);
     if (hitLayer) {

tests/layout/document-elementFromPoint-expected.txt

@@ -2,7 +2,9 @@ CONSOLE: unittest-suite-wait-for-done
 CONSOLE: PASS: should hit test
 CONSOLE: PASS: should hit test child and parent
 CONSOLE: PASS: should hit test child with layered parent
+CONSOLE: PASS: should hit test transformed child
+CONSOLE: PASS: should hit test canvas
 CONSOLE: 
-CONSOLE: All 3 tests passed.
+CONSOLE: All 5 tests passed.
 CONSOLE: unittest-suite-success
 DONE

tests/layout/document-elementFromPoint.sky

@@ -4,11 +4,13 @@ foo, parent { width: 100px; height: 100px; background: blue; }
 bar { width: 100px; height: 100px; background: purple; }
 parent { display: paragraph; }
 child { background: salmon; }
+canvas { height: 50px; background-color: pink; }
 </style>
 <foo /><bar />
 <parent>
   <child>Foo bar</child>
 </parent>
+<canvas />
 <script>
 import "../resources/third_party/unittest/unittest.dart";
 import "../resources/unit.dart";
@@ -48,6 +50,16 @@ void main() {
     document.querySelector('parent').style.setProperty("transform", "translate3d(0, 0, 0)");
     hitTestWithChildren();
   });
+
+  test("should hit test transformed child", () {
+    document.querySelector('child').style.setProperty("transform", "translate3d(100px, 0, 0)");
+    expect(document.elementFromPoint(50, 210).tagName, equals('parent'));
+    expect(document.elementFromPoint(150, 210).tagName, equals('child'));
+  });
+
+  test("should hit test canvas", () {
+    expect(document.elementFromPoint(50, 310).tagName, equals('canvas'));
+  });
 }
 </script>
 </sky>