Add simdutf dependency

Starting with https://crrev.com/c/6026354, V8 requires the simdutf
library to do conversions from base64.  Add this dependency for
PDFium as well for V8 build configurations.

Change-Id: I7fa92b23f5d7d7492b20d9714854f05ed10688ff
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/128850
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/.gitignore b/.gitignore
index 891f996..846ec7f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,6 +33,7 @@
 /third_party/ninja
 /third_party/rust
 /third_party/rust-toolchain
+/third_party/simdutf
 /third_party/skia
 /third_party/test_fonts
 /third_party/zlib
diff --git a/DEPS b/DEPS
index 2be8ed8..6e1da39 100644
--- a/DEPS
+++ b/DEPS
@@ -204,6 +204,10 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling skia
   # and whatever else without interference from each other.
+  'simdutf_revision': '5a9a2134b280c1b956ad68a0643797fe26dd1c94',
+  # Three lines of non-changing comments so that
+  # the commit queue can handle CLs rolling skia
+  # and whatever else without interference from each other.
   'skia_revision': '6f17f2ebb2e59a9fc7fdfdaa2f04fc77afc744a0',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling test_fonts
@@ -514,6 +518,12 @@
     ],
   },
 
+  'third_party/simdutf': {
+    'url': Var('chromium_git') + '/chromium/src/third_party/simdutf@' +
+        Var('simdutf_revision'),
+    'condition': 'checkout_v8',
+  },
+
   'third_party/skia': {
     'url': Var('skia_git') + '/skia.git@' + Var('skia_revision'),
     'condition': 'checkout_skia',