Route selection bounds updates through WebLayerTreeView

Source/web/tests/data/composited_selection_bounds_transformed.html

Index: Source/web/tests/data/composited_selection_bounds_transformed.html
diff --git a/Source/web/tests/data/composited_selection_bounds_transformed.html b/Source/web/tests/data/composited_selection_bounds_transformed.html
new file mode 100644
index 0000000000000000000000000000000000000000..5ad9cde7948288714fb3ae245419a29f6de86451
--- /dev/null
+++ b/Source/web/tests/data/composited_selection_bounds_transformed.html
@@ -0,0 +1,23 @@
+<style>
+    @font-face {
+        font-family: ahem;
+        src: url(Ahem.ttf);
+    }
+    * {
+        font-family: ahem;
+    }
+    #text {
+        transform: rotate(30deg);
+    }
+</style>
+<div id="text">The quick brown fox jumped over the lazy dog.</div>
+<script>
+    var range = document.createRange();
+    var textNode = document.getElementById("text").firstChild;
+    range.setStart(textNode, 10);
+    range.setEnd(textNode, 25);
+    document.getSelection().addRange(range);
+
+    window.expectedResult = [document, 157, -87, 151, -77, document, 313, 3, 307, 13];

[chrishtr, 2014/09/18 23:30:55]

Did you consider just adding a method to Internals and making these regular
layout tests? Why is the current approach better?

[trchen, 2014/09/19 00:10:02]

Yep I have considered that. Besides adding a function to query the current
selection bounds, we also need a bunch of functions to query internal
compositing details, because the layer ID may or may not be consistent between
runs. It turns out writing a WebFrameTest needs much fewer lines of code.

+</script>
+