Unify display ids between Display and PlatformDisplay.

services/ui/ws/platform_display.h

Index: services/ui/ws/platform_display.h
diff --git a/services/ui/ws/platform_display.h b/services/ui/ws/platform_display.h
index d7bc2f6033afbc69c355d9835c2638b4eff30fb3..4b4831d07a746fdc48eefa65be96cc28a8516007 100644
--- a/services/ui/ws/platform_display.h
+++ b/services/ui/ws/platform_display.h
@@ -52,10 +52,13 @@ class ServerWindow;
 // PlatformDisplay is used to connect the root ServerWindow to a display.
 class PlatformDisplay {
  public:
+  PlatformDisplay(int64_t id);

[msw, 2016/07/28 19:01:02]

Oh dang; I saw |set_factory_for_testing| and thought this was already an
abstract class, not a pure-virtual interface... I'm more hesitant to make this
change now, but feel free to proceed if you think it's okay. Feel free to
consult a more knowledgeable reviewer, like sky, rjkroege, or sadrul.

[kylechar, 2016/07/28 19:20:16]

I think sky is OOO but I'll talk with sadrul or rjkroege. It seems like it
should be okay, having an id is important now that we're using the
PlatformDisplay id for everything, so might as well implement it once.

   virtual ~PlatformDisplay() {}
 
   static PlatformDisplay* Create(const PlatformDisplayInitParams& init_params);
 
+  int64_t id() const { return id_; }
+
   virtual void Init(PlatformDisplayDelegate* delegate) = 0;
 
   // Schedules a paint for the specified region in the coordinates of |window|.
@@ -85,8 +88,6 @@ class PlatformDisplay {
   virtual void RequestCopyOfOutput(
       std::unique_ptr<cc::CopyOutputRequest> output_request) = 0;
 
-  virtual int64_t GetDisplayId() const = 0;
-
   virtual gfx::Rect GetBounds() const = 0;
 
   // Overrides factory for testing. Default (NULL) value indicates regular
@@ -96,6 +97,8 @@ class PlatformDisplay {
   }
 
  private:
+  int64_t id_;
+
   // Static factory instance (always NULL for non-test).
   static PlatformDisplayFactory* factory_;
 };

[msw, 2016/07/28 19:01:02]

nit: DISALLOW_COPY_AND_ASSIGN(PlatformDisplay); if not pure-virtual.

[kylechar, 2016/07/28 19:20:16]

Done.

@@ -125,7 +128,6 @@ class DefaultPlatformDisplay : public PlatformDisplay,
   bool IsFramePending() const override;
   void RequestCopyOfOutput(
       std::unique_ptr<cc::CopyOutputRequest> output_request) override;
-  int64_t GetDisplayId() const override;
   gfx::Rect GetBounds() const override;
 
  private:
@@ -150,8 +152,6 @@ class DefaultPlatformDisplay : public PlatformDisplay,
   bool IsInHighContrastMode() override;
   const ViewportMetrics& GetViewportMetrics() override;
 
-  int64_t display_id_;
-
 #if !defined(OS_ANDROID)
   std::unique_ptr<ui::CursorLoader> cursor_loader_;
 #endif