ui: Cleanup class/struct forward declarations

headless/lib/browser/headless_screen.cc

Index: headless/lib/browser/headless_screen.cc
diff --git a/headless/lib/browser/headless_screen.cc b/headless/lib/browser/headless_screen.cc
index c8be18bfdb1804dab9c759e8c04d70a924dcdd2b..be86924d2e3fc81ed7801995640ee6e9ee0ea726 100644
--- a/headless/lib/browser/headless_screen.cc
+++ b/headless/lib/browser/headless_screen.cc
@@ -12,7 +12,6 @@
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/ime/input_method.h"
-#include "ui/display/screen.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/native_widget_types.h"
@@ -37,7 +36,8 @@ HeadlessScreen::~HeadlessScreen() {}
 
 aura::WindowTreeHost* HeadlessScreen::CreateHostForPrimaryDisplay() {
   DCHECK(!host_);
-  host_ = aura::WindowTreeHost::Create(gfx::Rect(display_.GetSizeInPixel()));
+  host_ = aura::WindowTreeHost::Create(
+      gfx::Rect(GetPrimaryDisplay().GetSizeInPixel()));
   // Some tests don't correctly manage window focus/activation states.
   // Makes sure InputMethod is default focused so that IME basics can work.
   host_->GetInputMethod()->OnFocus();
@@ -47,50 +47,59 @@ aura::WindowTreeHost* HeadlessScreen::CreateHostForPrimaryDisplay() {
 }
 
 void HeadlessScreen::SetDeviceScaleFactor(float device_scale_factor) {
-  gfx::Rect bounds_in_pixel(display_.GetSizeInPixel());
-  display_.SetScaleAndBounds(device_scale_factor, bounds_in_pixel);
+  display::Display display(GetPrimaryDisplay());
+  gfx::Rect bounds_in_pixel(display.GetSizeInPixel());
+  display.SetScaleAndBounds(device_scale_factor, bounds_in_pixel);
+  display_list().UpdateDisplay(display);
 }
 
 void HeadlessScreen::SetDisplayRotation(display::Display::Rotation rotation) {
-  gfx::Rect bounds_in_pixel(display_.GetSizeInPixel());
+  display::Display display(GetPrimaryDisplay());
+  gfx::Rect bounds_in_pixel(display.GetSizeInPixel());
   gfx::Rect new_bounds(bounds_in_pixel);
-  if (IsRotationPortrait(rotation) != IsRotationPortrait(display_.rotation())) {
+  if (IsRotationPortrait(rotation) != IsRotationPortrait(display.rotation())) {
     new_bounds.set_width(bounds_in_pixel.height());
     new_bounds.set_height(bounds_in_pixel.width());
   }
-  display_.set_rotation(rotation);
-  display_.SetScaleAndBounds(display_.device_scale_factor(), new_bounds);
+  display.set_rotation(rotation);
+  display.SetScaleAndBounds(display.device_scale_factor(), new_bounds);
+  display_list().UpdateDisplay(display);
   host_->SetRootTransform(GetRotationTransform() * GetUIScaleTransform());
 }
 
 void HeadlessScreen::SetUIScale(float ui_scale) {
   ui_scale_ = ui_scale;
-  gfx::Rect bounds_in_pixel(display_.GetSizeInPixel());
+  display::Display display(GetPrimaryDisplay());
+  gfx::Rect bounds_in_pixel(display.GetSizeInPixel());
   gfx::Rect new_bounds = gfx::ToNearestRect(
       gfx::ScaleRect(gfx::RectF(bounds_in_pixel), 1.0f / ui_scale));
-  display_.SetScaleAndBounds(display_.device_scale_factor(), new_bounds);
+  display.SetScaleAndBounds(display.device_scale_factor(), new_bounds);
+  display_list().UpdateDisplay(display);
   host_->SetRootTransform(GetRotationTransform() * GetUIScaleTransform());
 }
 
 void HeadlessScreen::SetWorkAreaInsets(const gfx::Insets& insets) {
-  display_.UpdateWorkAreaFromInsets(insets);
+  display::Display display(GetPrimaryDisplay());
+  display.UpdateWorkAreaFromInsets(insets);
+  display_list().UpdateDisplay(display);
 }
 
 gfx::Transform HeadlessScreen::GetRotationTransform() const {
   gfx::Transform rotate;
-  switch (display_.rotation()) {
+  display::Display display(GetPrimaryDisplay());
+  switch (display.rotation()) {
     case display::Display::ROTATE_0:
       break;
     case display::Display::ROTATE_90:
-      rotate.Translate(display_.bounds().height(), 0);
+      rotate.Translate(display.bounds().height(), 0);
       rotate.Rotate(90);
       break;
     case display::Display::ROTATE_270:
-      rotate.Translate(0, display_.bounds().width());
+      rotate.Translate(0, display.bounds().width());
       rotate.Rotate(270);
       break;
     case display::Display::ROTATE_180:
-      rotate.Translate(display_.bounds().width(), display_.bounds().height());
+      rotate.Translate(display.bounds().width(), display.bounds().height());
       rotate.Rotate(180);
       break;
   }
@@ -108,8 +117,10 @@ void HeadlessScreen::OnWindowBoundsChanged(aura::Window* window,
                                            const gfx::Rect& old_bounds,
                                            const gfx::Rect& new_bounds) {
   DCHECK_EQ(host_->window(), window);
-  display_.SetSize(gfx::ScaleToFlooredSize(new_bounds.size(),
-                                           display_.device_scale_factor()));
+  display::Display display(GetPrimaryDisplay());
+  display.SetSize(gfx::ScaleToFlooredSize(new_bounds.size(),
+                                          display.device_scale_factor()));
+  display_list().UpdateDisplay(display);
 }
 
 void HeadlessScreen::OnWindowDestroying(aura::Window* window) {
@@ -132,42 +143,17 @@ gfx::NativeWindow HeadlessScreen::GetWindowAtScreenPoint(
   return host_->window()->GetTopWindowContainingPoint(point);
 }
 
-int HeadlessScreen::GetNumDisplays() const {
-  return 1;
-}
-
-std::vector<display::Display> HeadlessScreen::GetAllDisplays() const {
-  return std::vector<display::Display>(1, display_);
-}
-
 display::Display HeadlessScreen::GetDisplayNearestWindow(
     gfx::NativeWindow window) const {
-  return display_;
-}
-
-display::Display HeadlessScreen::GetDisplayNearestPoint(
-    const gfx::Point& point) const {
-  return display_;
+  return GetPrimaryDisplay();
 }
 
-display::Display HeadlessScreen::GetDisplayMatching(
-    const gfx::Rect& match_rect) const {
-  return display_;
-}
-
-display::Display HeadlessScreen::GetPrimaryDisplay() const {
-  return display_;
-}
-
-void HeadlessScreen::AddObserver(display::DisplayObserver* observer) {}
-
-void HeadlessScreen::RemoveObserver(display::DisplayObserver* observer) {}
-
 HeadlessScreen::HeadlessScreen(const gfx::Rect& screen_bounds)
     : host_(NULL), ui_scale_(1.0f) {
   static int64_t synthesized_display_id = 2000;
-  display_.set_id(synthesized_display_id++);
-  display_.SetScaleAndBounds(1.0f, screen_bounds);
+  display::Display display(synthesized_display_id++);
+  display.SetScaleAndBounds(1.0f, screen_bounds);
+  ProcessDisplayChanged(display, true /* is_primary */);
 }
 
 }  // namespace headless