Don't clobber the Simple Chrome cache at every gclient hook.

With crbug.com/834134, the cache will auto-evict old items. So there's
no need to clobber every time.

Bug: 834134
Change-Id: Idec34923ff9c6a30ddc633ab212d22a96bf3282f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212507Reviewed-by: Erik Chen <erikchen@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772008}

DEPS

@@ -4742,9 +4742,6 @@ hooks = [
       '--download-vm',
       '--boards={cros_boards}',
       '--cache-dir=src/build/cros_cache/',
-      # TODO(crbug.com/834134): Remove the cache clobber when the sdk is smart
-      # enough to eject old toolchains from the cache.
-      '--clear-sdk-cache',
       '--log-level=error',
       '--no-shell',
     ],