Merge remote-tracking branch 'refs/remotes/origin/Unity-2017.3' into Add-Per-Pixel-scale

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Editor/SubsurfaceScatteringProfileEditor.cs

                 {
                     // Validate each individual asset and update caches.
                     ((SubsurfaceScatteringProfile)target).Validate();
+                    hdPipeline.sssSettings.UpdateCache();
                 }
             }