Run install-sysroot script before 'gn gen' on PDFium bot

infra/bots/recipe_modules/flavor/pdfium_flavor.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import re
 
 import default_flavor
 
 
 """PDFium flavor utils, used for building PDFium with Skia."""
 
 
 class PDFiumFlavorUtils(default_flavor.DefaultFlavorUtils):
 
   def compile(self, target, **kwargs):
     """Build PDFium with Skia."""
     pdfium_dir = self.m.vars.checkout_root.join('pdfium')
 
     # Runhook to generate the gn binary in buildtools.
     self.m.run(
         self.m.step,
         'runhook',
         cmd=['gclient', 'runhook', 'gn_linux64'],
         cwd=pdfium_dir,
         **kwargs)
 
+    # Install the sysroot.
+    self.m.run(
+        self.m.step,
+        'sysroot',
+        cmd=['python', 'build/linux/sysroot_scripts/install-sysroot.py',
+             '--arch=amd64'],
+        cwd=pdfium_dir)
+
     # Setup gn args.
     gn_args = [
         'pdf_use_skia=true',
         'pdf_is_standalone=true',
         'clang_use_chrome_plugins=false',
         'is_component_build=false',
         'is_debug=false',
         ]
 
 
@@ skipping 30 matching lines @@
         cwd=pdfium_dir)
 
     # Build PDFium.
     self.m.run(
         self.m.step,
         'build_pdfium',
         cmd=['ninja', '-C', 'out/skia', '-j100'],
         cwd=pdfium_dir,
         env=env,
         **kwargs)