Reland change for aura tooltips that was revert due to build break:

ui/views/test/test_tooltip_client.cc

Index: ui/views/test/test_tooltip_client.cc
diff --git a/ui/views/test/test_tooltip_client.cc b/ui/views/test/test_tooltip_client.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e7ea34d9e4f989edbca6d509b07c465a7c903217
--- /dev/null
+++ b/ui/views/test/test_tooltip_client.cc
@@ -0,0 +1,28 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/test/test_tooltip_client.h"
+
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/font.h"
+#include "ui/gfx/point.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/screen.h"
+
+namespace aura {
+
+// static
+gfx::Font TooltipClient::GetDefaultFont() {
+  return ui::ResourceBundle::GetSharedInstance().GetFont(
+      ui::ResourceBundle::BaseFont);
+}
+
+// static
+int TooltipClient::GetMaxWidth(int x, int y) {
+  gfx::Rect monitor_bounds =
+      gfx::Screen::GetMonitorAreaNearestPoint(gfx::Point(x, y));
+  return (monitor_bounds.width() + 1) / 2;
+}
+
+}  // namespace aura