Fork a subset of ash/shelf for use in mash.

Fork Shelf View, Model, Button, TooltipManager, etc.
These provide a baseline of ash/shelf-like functionality.
(show open mash windows, support reordering, tooltips, etc.)

Restructure some ownership patterns (eg. shelf owns model).
Minimal code refactoring, removal and commenting.
(attempt to minimize diff, keep/stub some features)

TODO: Restore missing functionality/tests.

BUG=557406
TEST=mojo:mash_shell's shelf starts looking more like ash.
R=sky@chromium.org,bungeman@google.com

Review URL: https://codereview.chromium.org/1585363002

Cr-Commit-Position: refs/heads/master@{#371866}

mash/shelf/BUILD.gn

@@ -6,11 +6,25 @@ import("//build/config/ui.gni")
 import("//mojo/public/mojo_application.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
+# TODO(msw): Port unit/app tests: model, view, tooltip_manager, etc.
 mojo_native_application("shelf") {
   sources = [
     "main.cc",
     "shelf_application.cc",
     "shelf_application.h",
+    "shelf_button.cc",
+    "shelf_button.h",
+    "shelf_button_host.h",
+    "shelf_constants.cc",
+    "shelf_constants.h",
+    "shelf_item_types.cc",
+    "shelf_item_types.h",
+    "shelf_model.cc",
+    "shelf_model.h",
+    "shelf_model_observer.h",
+    "shelf_tooltip_manager.cc",
+    "shelf_tooltip_manager.h",
+    "shelf_types.h",
     "shelf_view.cc",
     "shelf_view.h",
   ]
@@ -24,9 +38,12 @@ mojo_native_application("shelf") {
     "//mojo/services/tracing/public/cpp",
     "//mojo/shell/public/cpp",
     "//skia",
+    "//ui/accessibility",
     "//ui/aura",
+    "//ui/resources",
     "//ui/views",
     "//ui/views/mus:for_mojo_application",
+    "//ui/wm",
   ]
 
   resources = [ "$root_out_dir/views_mus_resources.pak" ]

mash/shelf/DEPS

@@ -0,0 +1,3 @@
+include_rules = [
+  "+skia",
+]

mash/shelf/shelf_application.cc

@@ -27,11 +27,10 @@ void ShelfApplication::Initialize(mojo::ApplicationImpl* app) {
   aura_init_.reset(new views::AuraInit(app, "views_mus_resources.pak"));
   views::WindowManagerConnection::Create(app);
 
+  // Construct the shelf using a container tagged for positioning by the WM.
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
-  params.delegate = new ShelfView(app);
-
   std::map<std::string, std::vector<uint8_t>> properties;
   properties[mash::wm::mojom::kWindowContainer_Property] =
       mojo::TypeConverter<const std::vector<uint8_t>, int32_t>::Convert(
@@ -41,6 +40,9 @@ void ShelfApplication::Initialize(mojo::ApplicationImpl* app) {
   params.native_widget = new views::NativeWidgetMus(
       widget, app->shell(), window, mus::mojom::SurfaceType::DEFAULT);
   widget->Init(params);
+  widget->SetContentsView(new ShelfView(app));
+  // Call CenterWindow to mimic Widget::Init's placement with a widget delegate.
+  widget->CenterWindow(widget->GetContentsView()->GetPreferredSize());
   widget->Show();
 }