Pass device scale factor from display to ws.

services/ui/display/platform_screen_ozone.h

Index: services/ui/display/platform_screen_ozone.h
diff --git a/services/ui/display/platform_screen_ozone.h b/services/ui/display/platform_screen_ozone.h
index 88d2482227fd92521309e2492cf01cb583e317bc..b1ff23990d9dce2a74ee724399bca94e54a43f4e 100644
--- a/services/ui/display/platform_screen_ozone.h
+++ b/services/ui/display/platform_screen_ozone.h
@@ -47,12 +47,13 @@ class PlatformScreenOzone
   // TODO(kylechar): This struct is just temporary until we migrate
   // DisplayManager code out of ash so it can be used here.
   struct DisplayInfo {
-    DisplayInfo(int64_t new_id, const gfx::Rect& new_bounds)
-        : id(new_id), bounds(new_bounds) {}
-
-    int64_t id;
-    // The display bounds.
+    int64_t id = Display::kInvalidDisplayID;
+    // The display bounds in DIP.
     gfx::Rect bounds;
+    // Display size in DDP.
+    gfx::Size pixel_size;
+    // The display scale factor, either 1 or 2.

[rjkroege, 2016/09/21 13:23:47]

not so. it can be 1.25 yes?

And same blither about scale factor: it can be computed and not passed?

[kylechar, 2016/09/21 16:31:13]

It can sort of be 1.25. It's hard to explain without showing it?

For now I'm just ignoring 1.25 in PlatformScreen so the comment is accurate-ish.

+    float scale_factor = 1.0f;
     // The display bounds have been modified and delegate should be updated.
     bool modified = false;
     // The display has been removed and delegate should be updated.
@@ -90,6 +91,9 @@ class PlatformScreenOzone
   // iterator if there is no display with that id.
   CachedDisplayIterator GetCachedDisplayIterator(int64_t display_id);
 
+  // Converts |snapshot| into a DisplayInfo.
+  DisplayInfo DisplayInfoFromSnapshot(ui::DisplaySnapshot* snapshot);
+
   // ui::DisplayConfigurator::Observer:
   void OnDisplayModeChanged(
       const ui::DisplayConfigurator::DisplayStateList& displays) override;