[build] Revert pinned depot_tools to unbreak auto-roller

TBR=sergiyb@chromium.org

Bug: chromium:843917
Change-Id: I1b7efb5dd4fa7a87c84cc1bbfa7780a8600aad03
Reviewed-on: https://chromium-review.googlesource.com/1063750
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53227}

DEPS

@@ -16,7 +16,7 @@ deps = {
   'v8/tools/gyp':
     Var('chromium_url') + '/external/gyp.git' + '@' + 'd61a9397e668fa9843c4aa7da9e79460fe590bfb',
   'v8/third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '8de3800ce55ba459ffcbedcfa52ef5e6e59caab6',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '3f0591d4f12991ed39bae2dca96d3593879be382',
   'v8/third_party/icu':
     Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'e4194dc7bbb3305d84cbb1b294274ca70d230721',
   'v8/third_party/instrumented_libraries':