Fixes tests that use internals.observeGC to work with Ignition.

third_party/WebKit/LayoutTests/editing/input/text-input-controller-leak-document.html

Index: third_party/WebKit/LayoutTests/editing/input/text-input-controller-leak-document.html
diff --git a/third_party/WebKit/LayoutTests/editing/input/text-input-controller-leak-document.html b/third_party/WebKit/LayoutTests/editing/input/text-input-controller-leak-document.html
index 06e65c066f443b795aa844588804f375c755b69a..9ea98117be22d9f60ead394239f2b520c1ec3105 100644
--- a/third_party/WebKit/LayoutTests/editing/input/text-input-controller-leak-document.html
+++ b/third_party/WebKit/LayoutTests/editing/input/text-input-controller-leak-document.html
@@ -4,12 +4,19 @@
 
     <script src="../../resources/js-test.js"></script>
     <script>
-        var input = document.getElementById('text');
-        input.focus();
-        textInputController.setMarkedText("hello", 0, 5);
-        var markedRangeResultGC = internals.observeGC(textInputController.markedRange());
-        var selectedRangeResultGC = internals.observeGC(textInputController.selectedRange());
-        var firstRectForCharacterRangeGC = internals.observeGC(textInputController.firstRectForCharacterRange(0, 0));
+        var markedRangeResultGC;
+        var selectedRangeResultGC;
+        var firstRectForCharacterRangeGC;
+        var input;
+        function initializeVariables() {
+          input = document.getElementById('text');
+          input.focus();
+          textInputController.setMarkedText("hello", 0, 5);
+          markedRangeResultGC = internals.observeGC(textInputController.markedRange());
+          selectedRangeResultGC = internals.observeGC(textInputController.selectedRange());
+          firstRectForCharacterRangeGC = internals.observeGC(textInputController.firstRectForCharacterRange(0, 0));

[rmcilroy, 2016/05/05 13:50:46]

What actually lives in a temporary register and needs to be cleared here before
the GC for it to work? Presumably just the arguments to the observeGC calls.
Could we do something more clever by changing the observeGC API to ensure that
the arguments are never maintained in dead registers?

+        }
+        initializeVariables();
         gc();
         shouldBeTrue('markedRangeResultGC.wasCollected');
         shouldBeTrue('selectedRangeResultGC.wasCollected');