Roll buildtools 8d89c1b15f..e7111440c0

  In order to roll GN cdc76669..1b1e7e8c (r350849:r351089) and pick up
  the following changes:

  1b1e7e8c GN: Schedule config loads for sub-configs.
  c5598930 GN: Don't allow nested things inside template invocations.
  1c3192f7 Enhance GN documentation.
  e1bbf321 [GN]: Fix bug in roller script with try servers

TBR=dpranke@chromium.org
CQ_EXTRA_TRYBOTS=tryserver.chromium.mac:mac_chromium_gn_rel;tryserver.chromium.win:win8_chromium_gn_dbg,win_chromium_gn_x64_rel

Review URL: https://codereview.chromium.org/1370133006

Cr-Commit-Position: refs/heads/master@{#351142}

DEPS

@@ -50,7 +50,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling build tools
   # and whatever else without interference from each other.
-  'buildtools_revision': '8d89c1b15f80323b54b3305b2be7b26686fd5611',
+  'buildtools_revision': 'e7111440c07a883b82ffbbe6d26c744dfc6c9673',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.
@@ -811,3 +811,4 @@ hooks = [
   },
 ]
 
+