Use ResizeObserver and MutationObserver to detect detach/attach/resize (#7104)

* Use Resize/MutationObserver to detect detach/attach/resize
* Cleanup
* Review update
* Restore infinite resize detection (#6011)

package.json

@@ -34,7 +34,6 @@
     "@babel/plugin-transform-object-assign": "^7.8.3",
     "@babel/preset-env": "^7.8.4",
     "babel-preset-es2015-rollup": "^3.0.0",
-    "clean-css": "^4.2.3",
     "coveralls": "^3.0.9",
     "eslint": "^6.8.0",
     "eslint-config-chartjs": "^0.2.0",
@@ -66,6 +65,7 @@
     "merge-stream": "^1.0.1",
     "moment": "^2.10.2",
     "pixelmatch": "^5.0.0",
+    "resize-observer-polyfill": "^1.5.1",
     "rollup": "^1.31.0",
     "rollup-plugin-babel": "^4.3.3",
     "rollup-plugin-cleanup": "^3.1.1",