[WIP] Make content_shell run under Wayland

ui/views/widget/desktop_aura/desktop_screen_wayland.cc

+// Copyright 2016 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/widget/desktop_aura/desktop_screen_wayland.h"
+
+#include "ui/aura/window.h"
+#include "ui/ozone/public/ozone_platform.h"
+#include "ui/views/widget/desktop_aura/desktop_screen.h"
+
+namespace views {
+
+////////////////////////////////////////////////////////////////////////////////
+// DesktopScreenWayland, public:
+DesktopScreenWayland::DesktopScreenWayland()
+    : display::Screen(),
+      displays_() {
+  // Add a dummy Display.
+  // Without this, content_shell crashes in WindowTreeHost::InitCompositor()
+  // whiling calling GetDeviceScaleFactorFromDisplay() because the wl_output
+  // messages arrives later from Wayland Server.
+  displays_.push_back(display::Display(0, gfx::Rect(0, 0, 800, 600)));
+  ui::OzonePlatform::GetInstance()->SetScreenOutputObserver(this);
+}
+
+DesktopScreenWayland::~DesktopScreenWayland() {
+}
+
+// Overridden from display::Screen:
+gfx::Point DesktopScreenWayland::GetCursorScreenPoint() {
+  return gfx::Point();
+}
+
+bool DesktopScreenWayland::IsWindowUnderCursor(gfx::NativeWindow window) {
+  return true;
+}
+
+gfx::NativeWindow DesktopScreenWayland::GetWindowAtScreenPoint(
+    const gfx::Point& point) {
+  return nullptr;
+}
+
+int DesktopScreenWayland::GetNumDisplays() const {
+  return displays_.size();
+}
+
+std::vector<display::Display> DesktopScreenWayland::GetAllDisplays() const {
+  return displays_;
+}
+
+display::Display DesktopScreenWayland::GetDisplayNearestWindow(
+    gfx::NativeView window) const {
+  return GetPrimaryDisplay();
+}
+
+display::Display DesktopScreenWayland::GetDisplayNearestPoint(
+    const gfx::Point& point) const {
+  return GetPrimaryDisplay();
+}
+
+display::Display DesktopScreenWayland::GetDisplayMatching(
+    const gfx::Rect& match_rect) const {
+  return GetPrimaryDisplay();
+}
+
+display::Display DesktopScreenWayland::GetPrimaryDisplay() const {
+  DCHECK(!displays_.empty());
+  return displays_.front();
+}
+
+void DesktopScreenWayland::AddObserver(display::DisplayObserver* observer) {
+  change_notifier_.AddObserver(observer);
+}
+
+void DesktopScreenWayland::RemoveObserver(display::DisplayObserver* observer) {
+  change_notifier_.RemoveObserver(observer);
+}
+
+void DesktopScreenWayland::OnOutputGeometryChanged(int32_t name,
+   const gfx::Rect& rect) {
+  // Remove the dummy Display.
+  if (GetPrimaryDisplay().id() == 0 && displays_.size() == 1)
+    displays_.clear();
+
+  display::Display* matching = nullptr;
+  for (std::vector<display::Display>::iterator it = displays_.begin();
+      it != displays_.end(); ++it) {
+    if (name == it->id())
+      matching = &*it;
+  }
+
+  std::vector<display::Display> old_displays = displays_;
+
+  if (!matching)
+    displays_.push_back(display::Display(name, rect));
+  else
+    matching->set_bounds(rect);
+
+  change_notifier_.NotifyDisplaysChanged(old_displays, displays_);
+}
+
+}  // namespace views