Fix AXTreeSourceAuraTest.Accessors when Harmony is on.

When Harmony is enabled textfields have an additional child in the form
of the focus ring, so the expectation needed to be updated.

Bug: 846410
Change-Id: I0b807d7f69c97eed7bc56e9520f51d3a845fba76
Reviewed-on: https://chromium-review.googlesource.com/1103586Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568166}

chrome/browser/ui/ash/accessibility/ax_tree_source_aura_unittest.cc

@@ -18,6 +18,7 @@
 #include "ui/accessibility/ax_tree_serializer.h"
 #include "ui/accessibility/ax_tree_update.h"
 #include "ui/aura/window.h"
+#include "ui/base/material_design/material_design_controller.h"
 #include "ui/views/accessibility/ax_aura_obj_cache.h"
 #include "ui/views/accessibility/ax_aura_obj_wrapper.h"
 #include "ui/views/controls/textfield/textfield.h"
@@ -100,7 +101,10 @@ TEST_F(AXTreeSourceAuraTest, Accessors) {
   ASSERT_EQ(cached_textfield, textfield);
   std::vector<AXAuraObjWrapper*> textfield_children;
   ax_tree.GetChildren(textfield, &textfield_children);
-  ASSERT_EQ(1U, textfield_children.size());
+  // The textfield has an extra child in Harmony, the focus ring.
+  const size_t expected_children =
+      ui::MaterialDesignController::IsSecondaryUiMaterial() ? 2 : 1;
+  ASSERT_EQ(expected_children, textfield_children.size());
 
   ASSERT_EQ(content, textfield->GetParent());