Crash report: `ReferenceError: Can't find variable: ResizeObserver`

URL

https://app.uniswap.org/#/swap?chain=mainnet

swap state

{
  "independentField": "INPUT",
  "recipient": null,
  "INPUT": {
    "currencyId": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2"
  },
  "OUTPUT": {
    "currencyId": "0x138C2F1123cF3f82E4596d097c118eAc6684940B"
  },
  "typedValue": "0.03449"
}

Error

ReferenceError: Can't find variable: ResizeObserver

Stacktrace

https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2619968
https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2619690
https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2619803
Fs@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2798117
Fs@[native code]
https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2817328
Rs@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2794737
ws@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2790823
ws@[native code]
https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2740091
https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2817328
Yi@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2740037
Ki@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2739972
bs@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2787975
Ca@https://app.uniswap.org/static/js/2.cdb10fed.chunk.js:2:2759625
Ca@[native code]
https://app.uniswap.org/static/js/main.e5808ca6.chunk.js:1:515393

Device data

{
  "ua": "Mozilla/5.0 (iPhone; CPU iPhone OS 13_2_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 DeFiWallet/1.35.0",
  "browser": {
    "name": "WebKit",
    "version": "605.1.15",
    "major": "605"
  },
  "engine": {
    "name": "WebKit",
    "version": "605.1.15"
  },
  "os": {
    "name": "iOS",
    "version": "13.2.3"
  },
  "device": {
    "vendor": "Apple",
    "model": "iPhone",
    "type": "mobile"
  },
  "cpu": {}
}

Reproduce the swap URL on the reported iPhone iOS 13.2.3 WebKit environment, then inspect the stack locations in static/js/2.cdb10fed.chunk.js and static/js/main.e5808ca6.chunk.js. Trace the ResizeObserver failure back to its source and verify that the swap page no longer crashes in the reported environment.