Roll HarfBuzz to 1.8.3

https://chromium.googlesource.com/external/github.com/harfbuzz/harfbuzz/+log/058708a665cdd9e796581dbcf60a5778d3f5e240..2b76767bf572364d3d647cdd139f2044a7ad06b2

And disable HB_VECTOR_SIZE define now that HarfBuzz has temporarily
completed disabled compiler-assisted vectorisation.

Bug: 860250, 862607
Change-Id: If00101a279b23f5807a85973718183b33647195d
Reviewed-on: https://chromium-review.googlesource.com/1133384Reviewed-by: Ben Wagner <bungeman@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574407}

DEPS

@@ -161,7 +161,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling HarfBuzz
   # and whatever else without interference from each other.
-  'harfbuzz_revision': '058708a665cdd9e796581dbcf60a5778d3f5e240',
+  'harfbuzz_revision': '2b76767bf572364d3d647cdd139f2044a7ad06b2',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling catapult
   # and whatever else without interference from each other.

third_party/harfbuzz-ng/BUILD.gn

@@ -179,14 +179,6 @@ if (use_system_harfbuzz) {
       "HAVE_ICU_BUILTIN",
       "HAVE_INTEL_ATOMIC_PRIMITIVES",
       "HB_NO_MMAP",
-
-      # Define HB_VECTOR_SIZE to be 0 to disable compiler assisted
-      # vectorization. Compiler assisted vectorization is now disabled in
-      # upstream until posix_memalign() is used to align corresponding types.
-      # Compare
-      # https://chromium.googlesource.com/external/github.com/harfbuzz/harfbuzz/+/058708a665cdd9e796581dbcf60a5778d3f5e240%5E%21/#F0
-      # TODO(drott): Remove this after rolling past 1ebaa090d80bf0b59308d2c70f5e58dd8da47450
-      "HB_VECTOR_SIZE=0",
     ]
 
     if (is_component_build) {

third_party/harfbuzz-ng/README.chromium

 Name: harfbuzz-ng
 Short Name: harfbuzz-ng
 URL: http://harfbuzz.org
-Version: 1.8.2
-Date: 20180703
-Revision: 058708a665cdd9e796581dbcf60a5778d3f5e240
+Version: 1.8.3
+Date: 20180711
+Revision: 2b76767bf572364d3d647cdd139f2044a7ad06b2
 Security Critical: yes
 License: MIT
 License File: src/COPYING