Add GN conversions for more GYP flags

build/gyp_chromium

Index: build/gyp_chromium
diff --git a/build/gyp_chromium b/build/gyp_chromium
index 9818721bc60b98f4e90a045271cbb6ca4df09f0d..32cb491282ac27d470f016e03c50dfcac61bd264 100755
--- a/build/gyp_chromium
+++ b/build/gyp_chromium
@@ -115,6 +115,19 @@ def GetArgsStringForGN(supplemental_files):
   vars_dict = GetGypVarsForGN(supplemental_files)
   gn_args = ''
 
+  # Note: These are the additional flags passed to various builds by builders
+  # on the main waterfall. We'll probably need to add these at some point:
+  #   mac_strip_release=1         http://crbug.com/330301
+  #   linux_dump_symbols=0        http://crbug.com/330300
+  #   host_os=linux  Probably can skip, GN knows the host OS.
+  #   gcc_version=46  Hopefully we can skip this and fix whatever uses it.
+  #   order_text_section=<path>   http://crbug.com/330299
+  #   chromium_win_pch=0          http://crbug.com/297678
+  #   clang_use_chrome_plugins=1  http://crbug.com/330298
+  #   chromium_ios_signing=0      http://crbug.com/330302
+  #   linux_use_tcmalloc=0        http://crbug.com/330303
+  #   release_extra_flags=...     http://crbug.com/330305
+
   # These tuples of (key, value, gn_arg_string) use the gn_arg_string for
   # gn when the key is set to the given value in the GYP arguments.
   remap_cases = [
@@ -122,6 +135,18 @@ def GetArgsStringForGN(supplemental_files):
       ('buildtype', 'Official', 'is_official_build=true'),
       ('component', 'shared_library', 'is_component_build=true'),
       ('clang', '1', 'is_clang=true'),
+      ('target_arch', 'ia32', 'cpu_arch="x86"'),
+      ('target_arch', 'x64', 'cpu_arch="x64"'),
+      ('target_arch', 'arm', 'cpu_arch="arm"'),
+      ('fastbuild', '0', 'symbol_level=2'),
+      ('fastbuild', '1', 'symbol_level=1'),
+      ('fastbuild', '2', 'symbol_level=0'),
+      ('OS', 'ios', 'os="ios"'),
+      ('OS', 'android', 'os="android"'),
+      ('chromeos', '1', 'os="chromeos"'),
+      ('use_aura', '1', 'use_aura=true'),
+      ('asan', '1', 'is_asan=true'),
+      ('lsan', '1', 'is_lsan=true'),
   ]
   for i in remap_cases:
     if i[0] in vars_dict and vars_dict[i[0]] == i[1]: