ozone: Directly provide size of active mode from HardwareDisplayController

This change adds a GetModeSize() method that returns the size of the
HDC's output as a convenience.

TEST=Boot chrome on link_freon (and attach an external display.)
BUG=None

Review URL: https://codereview.chromium.org/535963002

Cr-Commit-Position: refs/heads/master@{#293161}

ui/ozone/platform/dri/dri_surface.cc

@@ -58,10 +58,8 @@ void DriSurface::ResizeCanvas(const gfx::Size& viewport_size) {
 
   // For the display buffers use the mode size since a |viewport_size| smaller
   // than the display size will not scanout.
-  gfx::Size mode_size(controller->get_mode().hdisplay,
-                      controller->get_mode().vdisplay);
   for (size_t i = 0; i < arraysize(buffers_); ++i)
-    buffers_[i] = AllocateBuffer(dri_, mode_size);
+    buffers_[i] = AllocateBuffer(dri_, controller->GetModeSize());
 }
 
 void DriSurface::PresentCanvas(const gfx::Rect& damage) {

ui/ozone/platform/dri/gbm_surface.cc

@@ -100,8 +100,7 @@ bool GbmSurface::Initialize() {
   // creation doesn't fail.
   gfx::Size size(1, 1);
   if (window_delegate_->GetController()) {
-    const drmModeModeInfo& mode = window_delegate_->GetController()->get_mode();
-    size.SetSize(mode.hdisplay, mode.vdisplay);
+    size = window_delegate_->GetController()->GetModeSize();
   }
   // TODO(dnicoara) Check underlying system support for pixel format.
   native_surface_ =

ui/ozone/platform/dri/hardware_display_controller.cc

@@ -258,6 +258,10 @@ bool HardwareDisplayController::IsDisabled() const {
   return is_disabled_;
 }
 
+gfx::Size HardwareDisplayController::GetModeSize() const {
+  return gfx::Size(mode_.hdisplay, mode_.vdisplay);
+}
+
 bool HardwareDisplayController::ModesetCrtc(
     const scoped_refptr<ScanoutBuffer>& buffer,
     drmModeModeInfo mode,

ui/ozone/platform/dri/hardware_display_controller.h

@@ -167,6 +167,7 @@ class HardwareDisplayController
   bool HasCrtc(uint32_t crtc) const;
   bool IsMirrored() const;
   bool IsDisabled() const;
+  gfx::Size GetModeSize() const;
 
   gfx::Point origin() const { return origin_; }
   void set_origin(const gfx::Point& origin) { origin_ = origin; }

ui/ozone/platform/dri/screen_manager.cc

@@ -16,14 +16,6 @@
 
 namespace ui {
 
-namespace {
-
-gfx::Size GetModeSize(const drmModeModeInfo& mode) {
-  return gfx::Size(mode.hdisplay, mode.vdisplay);
-}
-
-}  // namespace
-
 ScreenManager::ScreenManager(DriWrapper* dri,
                              ScanoutBufferGenerator* buffer_generator)
     : dri_(dri), buffer_generator_(buffer_generator) {
@@ -46,7 +38,8 @@ bool ScreenManager::ConfigureDisplayController(uint32_t crtc,
                                                uint32_t connector,
                                                const gfx::Point& origin,
                                                const drmModeModeInfo& mode) {
-  gfx::Rect modeset_bounds(origin, GetModeSize(mode));
+  gfx::Rect modeset_bounds(
+      origin.x(), origin.y(), mode.hdisplay, mode.vdisplay);
   HardwareDisplayControllers::iterator it = FindDisplayController(crtc);
   HardwareDisplayController* controller = NULL;
   if (it != controllers_.end()) {
@@ -143,8 +136,7 @@ ScreenManager::FindActiveDisplayControllerByLocation(const gfx::Rect& bounds) {
   for (HardwareDisplayControllers::iterator it = controllers_.begin();
        it != controllers_.end();
        ++it) {
-    gfx::Rect controller_bounds((*it)->origin(),
-                                GetModeSize((*it)->get_mode()));
+    gfx::Rect controller_bounds((*it)->origin(), (*it)->GetModeSize());
     // We don't perform a strict check since content_shell will have windows
     // smaller than the display size.
     if (controller_bounds.Contains(bounds) && !(*it)->IsDisabled())