hi-dpi: convert _NET_WORKAREA from pixels.

ui/views/widget/desktop_aura/desktop_screen_x11.cc

 // Copyright (c) 2012 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_x11.h"
 
 #include <X11/extensions/Xrandr.h>
 #include <X11/Xlib.h>
 
 // It clashes with out RootWindow.
 #undef RootWindow
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/layout.h"
 #include "ui/display/util/display_util.h"
 #include "ui/display/util/x11/edid_parser_x11.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/display.h"
+#include "ui/gfx/geometry/point_conversions.h"
+#include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/x/x11_types.h"
 #include "ui/views/widget/desktop_aura/desktop_screen.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h"
 #include "ui/views/widget/desktop_aura/x11_topmost_window_finder.h"
 
 namespace {
 
 // The delay to perform configuration after RRNotify.  See the comment
@@ skipping 227 matching lines @@
 std::vector<gfx::Display> DesktopScreenX11::BuildDisplaysFromXRandRInfo() {
   std::vector<gfx::Display> displays;
   XRRScreenResources* resources =
       XRRGetScreenResourcesCurrent(xdisplay_, x_root_window_);
   if (!resources) {
     LOG(ERROR) << "XRandR returned no displays. Falling back to Root Window.";
     return GetFallbackDisplayList();
   }
 
   bool has_work_area = false;
-  gfx::Rect work_area;
+  gfx::Rect work_area_in_pixels;
   std::vector<int> value;
   if (ui::GetIntArrayProperty(x_root_window_, "_NET_WORKAREA", &value) &&
       value.size() >= 4) {
-    work_area = gfx::Rect(value[0], value[1], value[2], value[3]);
+    work_area_in_pixels = gfx::Rect(value[0], value[1], value[2], value[3]);
     has_work_area = true;
   }
 
   float device_scale_factor = 1.0f;
   for (int i = 0; i < resources->noutput; ++i) {
     RROutput output_id = resources->outputs[i];
     XRROutputInfo* output_info =
         XRRGetOutputInfo(xdisplay_, resources, output_id);
 
     bool is_connected = (output_info->connection == RR_Connected);
@@ skipping 23 matching lines @@
           // As per display scale factor is not supported right now,
           // the primary display's scale factor is always used.
           device_scale_factor = GetDeviceScaleFactor(crtc->width,
                                                      output_info->mm_width);
           DCHECK_LE(1.0f, device_scale_factor);
         }
         display.SetScaleAndBounds(device_scale_factor, crtc_bounds);
       }
 
       if (has_work_area) {
-        gfx::Rect intersection = crtc_bounds;
-        intersection.Intersect(work_area);
-        display.set_work_area(intersection);
+        gfx::Rect intersection_in_pixels = crtc_bounds;
+        intersection_in_pixels.Intersect(work_area_in_pixels);
+        // SetScaleAndBounds() above does the conversion from pixels to DIP for
+        // us, but set_work_area does not, so we need to do it here.
+        display.set_work_area(gfx::Rect(
+            gfx::ToFlooredPoint(
+                gfx::ScalePoint(intersection_in_pixels.origin(),
+                                1.0f / display.device_scale_factor())),
+            gfx::ToFlooredSize(
+                gfx::ScaleSize(intersection_in_pixels.size(),
+                               1.0f / display.device_scale_factor()))));
       }
 
       switch (crtc->rotation) {
         case RR_Rotate_0:
           display.set_rotation(gfx::Display::ROTATE_0);
           break;
         case RR_Rotate_90:
           display.set_rotation(gfx::Display::ROTATE_90);
           break;
         case RR_Rotate_180:
@@ skipping 27 matching lines @@
   change_notifier_.NotifyDisplaysChanged(old_displays, displays_);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 gfx::Screen* CreateDesktopScreen() {
   return new DesktopScreenX11;
 }
 
 }  // namespace views