Roll icu to 53f6b2

https://chromium.googlesource.com/chromium/deps/icu.git/+log/952ccb9..53f6b23

  53f6b23 Fix leakage in adoptCalendar

Bug: chromium:997401
Change-Id: I3e152496ac9e4ee6bf2c95e90d23e489d672ff68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1777048
Commit-Queue: Jungshik Shin <jshin@chromium.org>
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692223}

DEPS

@@ -1027,7 +1027,7 @@ deps = {
     Var('chromium_git') + '/chromium/deps/hunspell_dictionaries.git' + '@' + '681ca92480ecc11d35feae8c1c00e4e035630f43',
 
   'src/third_party/icu':
-    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '952ccb90fb669bb70015cabe64ce415708f125bf',
+    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '53f6b233a41ec982d8445996247093f7aaf41639',
 
   'src/third_party/icu4j': {
       'packages': [