[OverlayWindow] Add platform-independent window and views implementation.

chrome/browser/ui/views/overlay/overlay_window_views.cc

+// 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.
+
+#include "chrome/browser/ui/views/overlay/overlay_window_views.h"
+
+// static
+std::unique_ptr<OverlayWindow> OverlayWindow::Create() {
+  return base::WrapUnique(new OverlayWindowViews());
+}
+
+OverlayWindowViews::OverlayWindowViews() : widget_(new views::Widget()) {}
+
+OverlayWindowViews::~OverlayWindowViews() = default;

[sky, 2017/06/20 16:51:39]

It's not clear what the ownership model is you're going for here. The way you
have it now the widget_ may outlive OverlayWindowViews, e.g. the following leaks
the widget_:

{
  OverlayWindow::Create();
}

[apacible, 2017/06/24 00:42:03]

Updated.

+
+void OverlayWindowViews::Init() {
+  // TODO(apacible): Finalize the type of widget.
+  views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
+
+  // TODO(apacible): Update preferred sizing and positioning.
+  params.bounds = gfx::Rect(200, 200, 700, 500);
+  params.keep_on_top = true;
+  params.visible_on_all_workspaces = true;
+
+  widget_->Init(params);
+  widget_->Show();
+
+  // TODO(apacible): Set the WidgetDelegate for more control over behavior.
+}
+
+ui::Layer* OverlayWindowViews::GetLayer() {
+  return widget_->GetLayer();
+}
+
+bool OverlayWindowViews::IsActive() const {
+  return widget_->IsActive();
+}
+
+// Window is never maximized.
+bool OverlayWindowViews::IsMaximized() const {
+  return false;
+}
+
+// Window is never minimized.
+bool OverlayWindowViews::IsMinimized() const {
+  return false;
+}
+
+// Window is never fullscreened.
+bool OverlayWindowViews::IsFullscreen() const {
+  return false;
+}
+
+gfx::NativeWindow OverlayWindowViews::GetNativeWindow() const {
+  return widget_->GetNativeWindow();
+}
+
+gfx::Rect OverlayWindowViews::GetRestoredBounds() const {
+  return GetBounds();
+}
+
+// Returns the restore state for the window (platform dependent).
+ui::WindowShowState OverlayWindowViews::GetRestoredState() const {
+  return ui::SHOW_STATE_NORMAL;
+}
+
+// Retrieves the window's current bounds, including its window.
+// This will only differ from GetRestoredBounds() for maximized
+// and minimized windows.
+gfx::Rect OverlayWindowViews::GetBounds() const {
+  return widget_->GetRestoredBounds();
+}
+
+void OverlayWindowViews::Show() {
+  widget_->Show();
+}
+
+void OverlayWindowViews::Hide() {
+  widget_->Hide();
+}
+
+void OverlayWindowViews::ShowInactive() {
+  NOTREACHED();
+}
+
+void OverlayWindowViews::Close() {
+  widget_->Close();
+}
+
+void OverlayWindowViews::Activate() {
+  widget_->Activate();
+}
+
+void OverlayWindowViews::Deactivate() {
+  NOTREACHED();

[sky, 2017/06/20 16:51:39]

Why do you have a bunch of NOTREACHEDs? If they are going to be NOTREACHED in
the long term, what are you gaining by subclassing BaseWindow? In other words,
why is OverlayWindow a BaseWindow rather than only containing the methods you
care about?

[apacible, 2017/06/24 00:42:03]

These will be filled out later. A couple functions, like minimize(), will likely
not do anything (need to iterate with UX) if we always want the window to
appear.

[sky, 2017/06/26 15:38:44]

It's hard for me to readily tell from this cl what are you gaining by
subclassing BaseWindow?

+}
+
+void OverlayWindowViews::Maximize() {
+  NOTREACHED();
+}
+
+void OverlayWindowViews::Minimize() {
+  NOTREACHED();
+}
+
+void OverlayWindowViews::Restore() {
+  NOTREACHED();
+}
+
+void OverlayWindowViews::SetBounds(const gfx::Rect& bounds) {
+  NOTREACHED();
+}
+
+void OverlayWindowViews::FlashFrame(bool flash) {
+  NOTREACHED();
+}
+
+bool OverlayWindowViews::IsAlwaysOnTop() const {
+  return true;
+}
+
+void OverlayWindowViews::SetAlwaysOnTop(bool always_on_top) {
+  NOTREACHED();
+}