Merge pull request #1400 from Unity-Technologies/Fix-issue-with-SetViewmporAndClear

Update changelog

com.unity.render-pipelines.high-definition/CHANGELOG.md

 - Fix directional light and shadow mask transition, they are now matching making smooth transition
 - Fix banding issues caused by high intensity volumetric lighting
 - Fix the debug window being emptied on SRP asset reload
+- Fix issue with debug mode not correctly clearing the GBuffer in editor after a resize
 
 ## [2018.1.0f2]