Added showing slow scroll rectangles in Layers panel.

LayoutTests/inspector/layers/layer-scroll-rects-update-expected.txt

Index: LayoutTests/inspector/layers/layer-scroll-rects-update-expected.txt
diff --git a/LayoutTests/inspector/layers/layer-scroll-rects-update-expected.txt b/LayoutTests/inspector/layers/layer-scroll-rects-update-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..ecfa60f87e8cf2a33f6412fc9375f430814a2f52
--- /dev/null
+++ b/LayoutTests/inspector/layers/layer-scroll-rects-update-expected.txt
@@ -0,0 +1,159 @@
+Initial scroll rectangles
+View elements dump
+scroll-rect: {
+    className : "scroll-rect"
+    height : "29px"
+    left : "0px"
+    title : "repaints on scroll"
+    top : "29px"
+    width : "29px"
+}
+scroll-rect: {
+    className : "scroll-rect"
+    height : "29px"
+    left : "29px"
+    title : "mousewheel event listener"
+    top : "29px"
+    width : "29px"
+}
+scroll-rect: {
+    className : "scroll-rect"
+    height : "29px"
+    left : "29px"
+    title : "touch event listener"
+    top : "0px"
+    width : "29px"
+}
+scroll-rect: {
+    className : "scroll-rect"
+    height : "29px"
+    left : "0px"
+    title : "touch event listener"
+    top : "0px"
+    width : "29px"
+}
+Model elements dump
+{
+}
+{
+    0 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 0
+            y : 10
+        }
+        type : "RepaintsOnScroll"
+    }
+}
+{
+    0 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 10
+            y : 10
+        }
+        type : "WheelEventHandler"
+    }
+    1 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 10
+            y : 0
+        }
+        type : "TouchEventHandler"
+    }
+}
+{
+    0 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 0
+            y : 0
+        }
+        type : "TouchEventHandler"
+    }
+}
+Updated scroll rectangles
+View elements dump
+scroll-rect: {
+    __unchanged : true
+    className : "scroll-rect"
+    height : "29px"
+    left : "0px"
+    title : "mousewheel event listener"
+    top : "0px"
+    width : "29px"
+}
+scroll-rect: {
+    __unchanged : true
+    className : "scroll-rect"
+    height : "29px"
+    left : "29px"
+    title : "touch event listener"
+    top : "0px"
+    width : "29px"
+}
+scroll-rect: {
+    className : "scroll-rect"
+    height : "29px"
+    left : "0px"
+    title : "touch event listener"
+    top : "0px"
+    width : "29px"
+}
+scroll-rect: {
+    className : "scroll-rect"
+    height : "29px"
+    left : "29px"
+    title : "touch event listener"
+    top : "29px"
+    width : "29px"
+}
+Model elements dump
+{
+}
+{
+    0 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 0
+            y : 0
+        }
+        type : "WheelEventHandler"
+    }
+    1 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 10
+            y : 0
+        }
+        type : "TouchEventHandler"
+    }
+}
+{
+    0 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 0
+            y : 0
+        }
+        type : "TouchEventHandler"
+    }
+    1 : {
+        rect : {
+            height : 10
+            width : 10
+            x : 10
+            y : 10
+        }
+        type : "TouchEventHandler"
+    }
+}
+