Update and pin tools_rev

Pinned due to dart-lang/tools#2034
- revert PR: dart-lang/tools#2064
- re-land PR: dart-lang/tools#2065

Bug: flutter/devtools#8944
Change-Id: I604c5dcc1e7e12b729ceb47e2549e373c4dc3c5a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/420801
Commit-Queue: Elliott Brooks <[email protected]>
Reviewed-by: Devon Carew <[email protected]>

Author: elliette

DEPS

@@ -144,7 +144,7 @@ vars = {
   "sync_http_rev": "dc54465f07d9652875deeade643256dafa2fbc6c",
   "tar_rev": "5a1ea943e70cdf3fa5e1102cdbb9418bd9b4b81a",
   "test_rev": "c1fa1e692084a9aab83a171cdcffcc4087e8e40b",
-  "tools_rev": "62bc13bc086a66ce9a6a3e64865c82d17a1379b3", # dart-lang/tools/pull/2034
+  "tools_rev": "8d49319b95912a5dff3d7ba4cd861458c55c5608", # dart-lang/tools/pull/2065
   "vector_math_rev": "f08d7d2652e9ecf7d8f8605d9983335174511c95",
   "web_rev": "5a39fdc396ae40344308975140343c23b6863261",
   "webdev_rev": "697f2f7f56517b0678c6256e0834778905acfc0d",