HDR: Do nonlinear blending in the compositor

ui/compositor/test/in_process_context_factory.h

Index: ui/compositor/test/in_process_context_factory.h
diff --git a/ui/compositor/test/in_process_context_factory.h b/ui/compositor/test/in_process_context_factory.h
index 9d40c12143c34b409d14d4844bac20e369c0d1cc..972c3358f1429ac661abf024d3c2fbdb0baa3f2a 100644
--- a/ui/compositor/test/in_process_context_factory.h
+++ b/ui/compositor/test/in_process_context_factory.h
@@ -63,8 +63,10 @@ class InProcessContextFactory : public ContextFactory,
   void SetDisplayVisible(ui::Compositor* compositor, bool visible) override;
   void ResizeDisplay(ui::Compositor* compositor,
                      const gfx::Size& size) override;
-  void SetDisplayColorSpace(ui::Compositor* compositor,
-                            const gfx::ColorSpace& color_space) override {}
+  void SetDisplayColorSpace(
+      ui::Compositor* compositor,
+      const gfx::ColorSpace& blending_color_space,
+      const gfx::ColorSpace& output_color_space) override {}
   void SetAuthoritativeVSyncInterval(ui::Compositor* compositor,
                                      base::TimeDelta interval) override {}
   void SetDisplayVSyncParameters(ui::Compositor* compositor,