android: disable ThinLTO for official builds

This is a workaround for an apparently broken compiler roll, which is
blocking Clank canary releases. It should be reverted before we branch
for 77.

Bug: 973431
Binary-Size: ThinLTO saves us binary size. This is a workaround.
Change-Id: Id08e12acbc4a64a83d476139713d2da3fece3a62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1661128
Commit-Queue: George Burgess <gbiv@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#669438}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4f7e1019a72eac00eb343baa4b0c5887c546ec23
diff --git a/compiler/compiler.gni b/compiler/compiler.gni
index c351d6b..eb5f728 100644
--- a/compiler/compiler.gni
+++ b/compiler/compiler.gni
@@ -57,7 +57,9 @@
 
   # Enables support for ThinLTO, which links 3x-10x faster than full LTO. See
   # also http://blog.llvm.org/2016/06/thinlto-scalable-and-incremental-lto.html
-  use_thin_lto = is_cfi || (is_android && is_official_build)
+  # TODO(crbug.com/973431): reenable this for x86 Android when clang gets fixed
+  use_thin_lto =
+      is_cfi || (is_android && is_official_build && current_cpu != "x86")
 
   # Tell VS to create a PDB that references information in .obj files rather
   # than copying it all. This should improve linker performance. mspdbcmf.exe