[ios clean] Adds ToolsMenu to Showcase.

ios/showcase/tools_menu/BUILD.gn

Index: ios/showcase/tools_menu/BUILD.gn
diff --git a/ios/showcase/tools_menu/BUILD.gn b/ios/showcase/tools_menu/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..91632ce05d7ed5d9674bb26a858b17aad113e52e
--- /dev/null
+++ b/ios/showcase/tools_menu/BUILD.gn
@@ -0,0 +1,20 @@
+# Copyright 2017 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.
+
+source_set("tools_menu") {
+  sources = [
+    "sc_tools_coordinator.h",
+    "sc_tools_coordinator.mm",
+  ]
+  deps = [
+    "//base",
+    "//ios/clean/chrome/browser/ui/commands",
+    "//ios/clean/chrome/browser/ui/tools:tools",

[lpromero, 2017/06/19 09:38:49]

We shouldn't add this target as a dependency in Showcase. This is to get
itemsModelList. Even if it has model in its name, should it be moved to the
tools_ui target?
Otherwise, in Showcase, we need to mock it, maybe even with bogus values.

[sczs, 2017/06/19 19:44:38]

I've created a new target for the model, I think it makes sense and it solves
our problem. I guess I could also rename tools to tools_controller, I think it
could be a nice "standard" to have across the app. WDYT? 

+    "//ios/clean/chrome/browser/ui/tools:tools_ui",
+    "//ios/showcase/common",
+    "//ui/base",
+  ]
+  libs = [ "UIKit.framework" ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+}