Do not use assets for Ash window control button backgrounds

ash/ash_layout_constants.cc

Index: ash/ash_layout_constants.cc
diff --git a/ash/ash_layout_constants.cc b/ash/ash_layout_constants.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bb154fa2a4d1ea4a8758bdbc0b996c3699cb21c6
--- /dev/null
+++ b/ash/ash_layout_constants.cc
@@ -0,0 +1,36 @@
+// Copyright 2015 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 "ash/ash_layout_constants.h"
+
+#include "base/logging.h"
+#include "ui/base/resource/material_design/material_design_controller.h"
+
+gfx::Size GetAshLayoutSize(AshLayoutSize size) {
+  const int kBrowserMaximizedHeaderButtonHeight[] = {27, 32, 36};
+  const int kBrowserMaximizedHeaderButtonWidth[] = {35, 32, 32};
+  const int kBrowserRestoredHeaderButtonHeight[] = {35, 36, 40};
+  const int kBrowserRestoredHeaderButtonWidth[] = {35, 32, 32};
+  const int kDefaultHeaderButtonHeight[] = {33, 33, 33};
+  const int kDefaultHeaderButtonWidth[] = {32, 32, 32};
+
+  const int mode = ui::MaterialDesignController::GetMode();
+  switch (size) {
+    case BROWSER_MAXIMIZED_HEADER_BUTTON: {
+      return gfx::Size(kBrowserMaximizedHeaderButtonWidth[mode],
+                       kBrowserMaximizedHeaderButtonHeight[mode]);
+    }
+    case BROWSER_RESTORED_HEADER_BUTTON: {
+      return gfx::Size(kBrowserRestoredHeaderButtonWidth[mode],
+                       kBrowserRestoredHeaderButtonHeight[mode]);
+    }
+    case DEFAULT_HEADER_BUTTON: {
+      return gfx::Size(kDefaultHeaderButtonWidth[mode],
+                       kDefaultHeaderButtonHeight[mode]);
+    }
+  }
+
+  NOTREACHED();
+  return gfx::Size();
+}