Roll GN from 81ee1967 to 8c7f4910

https://gn.googlesource.com/gn.git/+log/81ee1967..8c7f4910

8c7f491 rust: fix build on older clang by Tomasz Ĺšniatowski
8f8178c Escape prerequisites filenames in build.ninja.d depfile by samogot
89d5ef5 Minor fixes to tracing by Julie Hockett
ae93998 An example Rust build by Julie Hockett
80a5dc0 Ninja rules for Rust by Julie Hockett
e906492 Rust GN target generation by Julie Hockett
586b028 Rust compilation tool and toolchain support by Julie Hockett
ed8b690 rust_library and Rust-specific variables by Julie Hockett
5b16fb9 Rust substitutions and config values by Julie Hockett
b89110a Move SourceFileTypeSet to Target by Julie Hockett
95a92a9 [espace.h] fix comment by Takuto Ikuta
17cc456 json_project_writer: Output response_file_contents for action and action_for_each by Kimmo Kinnunen
36c66bf Add additional surce files and example the list of acceptable files by Julie Hockett
04f5df5 [args] Fix gn args unstable output by Haowei Wu
bc3fe2a [gen.py] Use relative -I switches and source paths by Roland McGrath
8730b0f Disallow non-buildable sources in binary targets by Tom Anderson
0d038c2 Cache source file type in SourceFile by Tom Anderson

BUG=964411
R=dpranke

Change-Id: Ib9ea522a075fba2ca81b91ab347731a7829901b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1650093
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#669546}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 221c6f3dad0073f21079673f7b05a5ac88e13a95
diff --git a/DEPS b/DEPS
index 4b944b9..d7a54d4 100644
--- a/DEPS
+++ b/DEPS
@@ -14,7 +14,7 @@
   #
 
   # GN CIPD package version.
-  'gn_version': 'git_revision:81ee1967d3fcbc829bac1c005c3da59739c88df9',
+  'gn_version': 'git_revision:8c7f49102234f4f4b9349dcb258554675475e596',
 
   # When changing these, also update the svn revisions in deps_revisions.gni
   'clang_format_revision': '96636aa0e9f047f17447f2d45a094d0b59ed7917',