Revert "Roll src/third_party/icu/ 79326efe2..d7eebbfb2 (4 commits)"

This reverts commit 885496b1.

Reason for revert: build failures on chromeos-chrome uprev

Original change's description:
> Roll src/third_party/icu/ 79326efe2..d7eebbfb2 (4 commits)
> 
> https://chromium.googlesource.com/chromium/deps/icu.git/+log/79326efe26e5..d7eebbfb276a
> 
> $ git log 79326efe2..d7eebbfb2 --date=short --no-merges --format='%ad %ae %s'
> 2020-09-16 hidehiko icu: Expand is_linux to is_linux || is_chromeos.
> 2020-09-11 fdegans [fuchsia] Bring more changes from the Fuchsia copy
> 2020-09-01 fdegans Upstream Fuchsia changes in build file
> 2020-06-29 adetaylor Add CPEPrefix.
> 
> Created with:
>   roll-dep src/third_party/icu
> 
> Bug: 1110266
> Change-Id: I41906106d93794e7d11d65571512e9bea85352e2
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2413511
> Reviewed-by: Eliot Courtney <edcourtney@chromium.org>
> Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#807389}

TBR=hidehiko@chromium.org,edcourtney@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1110266
Change-Id: Icae9eb5bd44fe2553cfcf3ee80c06b51bd7df62c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416735Reviewed-by: Jun Mukai <mukai@chromium.org>
Reviewed-by: Fabrice de Gans-Riberi <fdegans@chromium.org>
Commit-Queue: Jun Mukai <mukai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808005}

DEPS

@@ -1027,7 +1027,7 @@ deps = {
     Var('chromium_git') + '/chromium/deps/hunspell_dictionaries.git' + '@' + '18e09b9197a3b1d771c077c530d1a4ebad04c167',
 
   'src/third_party/icu':
-    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + 'd7eebbfb276a1b5c90edc26eeaf5fd43d6ccc2a1',
+    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '79326efe26e5440f530963704c3c0ff965b3a4ac',
 
   'src/third_party/icu4j': {
       'packages': [