Implement a Hit Test Cache.

LayoutTests/fast/events/hit-test-counts-expected.txt

Index: LayoutTests/fast/events/hit-test-counts-expected.txt
diff --git a/LayoutTests/fast/events/hit-test-counts-expected.txt b/LayoutTests/fast/events/hit-test-counts-expected.txt
index 129629297899353966c8823ca6e4ada8d0d7836c..4c52d990b798877f3e582caeedcd2ffd5320b2b3 100644
--- a/LayoutTests/fast/events/hit-test-counts-expected.txt
+++ b/LayoutTests/fast/events/hit-test-counts-expected.txt
@@ -6,76 +6,82 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 PASS successfullyParsed is true
 
 TEST COMPLETE
+PASS successfullyParsed is true
+
+TEST COMPLETE
 Event on a simple div
 ---------------------
-Initial: 0
-MouseMove: 1
-MouseDown: 3
-MouseUp: 1
-Wheel: 1
-TouchStart: 1
-TouchMove: 0
-TouchEnd: 0
-GestureTapDown: 2
-GestureShowPress: 2
-GestureTap: 4 [with multiTargetTapNotification: 5]
-GestureScrollBegin: 1
-GestureTapCancel: 1
-GestureScrollUpdate: 0
-GestureScrollEnd: 0
+Initial: 0+0
+MouseMove: 1+0
+MouseDown: 1+2
+MouseUp: 0+1
+Wheel: 0+1
+TouchStart: 1+0
+TouchMove: 0+0
+TouchEnd: 0+0
+GestureTapDown: 1+1
+GestureShowPress: 1+1
+GestureTap: 1+3 [with multiTargetTapNotification: 1+4]
+GestureScrollBegin: 0+1
+GestureTapCancel: 1+0
+GestureScrollUpdate: 0+0
+GestureScrollEnd: 0+0
 
 Event entirely over one iframe nested in another
 ---------------------
-Initial: 0 0 0
-MouseMove: 1 1 1
-MouseDown: 2 2 2
-MouseUp: 1 1 1
-Wheel: 1 1 1
-TouchStart: 1 1 1
-TouchMove: 0 0 0
-TouchEnd: 0 0 0
-GestureTapDown: 1 1 2
-GestureShowPress: 1 1 2
-GestureTap: 1 1 4
-GestureScrollBegin: 1 1 1
-GestureTapCancel: 1 1 1
-GestureScrollUpdate: 0 0 0
-GestureScrollEnd: 0 0 0
+Initial: 0+0 0+0 0+0
+MouseMove: 1+0 1+0 1+0
+MouseDown: 1+1 1+1 1+1
+MouseUp: 0+1 0+1 0+1
+Wheel: 0+1 0+1 0+1
+TouchStart: 1+0 1+0 1+0
+TouchMove: 0+0 0+0 0+0
+TouchEnd: 0+0 0+0 0+0
+GestureTapDown: 1+0 1+0 1+1
+GestureShowPress: 1+0 1+0 1+1
+GestureTap: 1+0 1+0 1+3
+GestureScrollBegin: 0+1 0+1 0+1
+GestureTapCancel: 1+0 1+0 1+0
+GestureScrollUpdate: 0+0 0+0 0+0
+GestureScrollEnd: 0+0 0+0 0+0
 
 Event near boundary of two iframes
 ---------------------
-Initial: 0 0 0
-MouseMove: 1 1 0
-MouseDown: 2 2 0
-MouseUp: 1 1 0
-Wheel: 1 1 0
-TouchStart: 1 1 0
-TouchMove: 0 0 0
-TouchEnd: 0 0 0
-GestureTapDown: 1 4 16
-GestureShowPress: 1 4 16
-GestureTap: 1 4 16 [with multiTargetTapNotification: 2 8 32]
-GestureScrollBegin: 1 1 0
-GestureTapCancel: 1 1 0
-GestureScrollUpdate: 0 0 0
-GestureScrollEnd: 0 0 0
+Initial: 0+0 0+0 0+0
+MouseMove: 1+0 1+0 0+0
+MouseDown: 1+1 1+1 0+0
+MouseUp: 0+1 0+1 0+0
+Wheel: 0+1 0+1 0+0
+TouchStart: 1+0 1+0 0+0
+TouchMove: 0+0 0+0 0+0
+TouchEnd: 0+0 0+0 0+0
+GestureTapDown: 1+0 4+0 16+0
+GestureShowPress: 1+0 4+0 16+0
+GestureTap: 1+0 4+0 16+0
+GestureScrollBegin: 0+1 0+1 0+0
+GestureTapCancel: 1+0 0+1 0+0
+GestureScrollUpdate: 0+0 0+0 0+0
+GestureScrollEnd: 0+0 0+0 0+0
 
 Event on a simple div (desktop viewport)
 ---------------------
-Initial: 0
-MouseMove: 1
-MouseDown: 3
-MouseUp: 1
-Wheel: 1
-TouchStart: 1
-TouchMove: 0
-TouchEnd: 0
-GestureTapDown: 2
-GestureShowPress: 2
-GestureTap: 4 [with multiTargetTapNotification: 6]
-GestureScrollBegin: 1
-GestureTapCancel: 1
-GestureScrollUpdate: 0
-GestureScrollEnd: 0
+Initial: 0+0
+MouseMove: 1+0
+MouseDown: 1+2
+MouseUp: 0+1
+Wheel: 0+1
+TouchStart: 1+0
+TouchMove: 0+0
+TouchEnd: 0+0
+GestureTapDown: 1+1
+GestureShowPress: 1+1
+GestureTap: 1+3 [with multiTargetTapNotification: 2+4]
+GestureScrollBegin: 0+1
+GestureTapCancel: 1+0
+GestureScrollUpdate: 0+0
+GestureScrollEnd: 0+0
 
+PASS successfullyParsed is true
+
+TEST COMPLETE