libchrome: Disable "-z,defs" for coverage builds.

Coverage builds do not like the linker flag "-z,defs" like asan.

Building libchrome with USE="coverage fuzzer" results in linker errors:

../../../libchrome-462023/platform2/libchrome/base/debug/activity_tracker.cc:152:
error: undefined reference to '__sanitizer_cov_trace_cmp4'
../../../libchrome-462023/platform2/libchrome/base/debug/activity_tracker.cc:572:
error: undefined reference to '__sanitizer_cov_trace_const_cmp2'
../../../libchrome-462023/platform2/libchrome/base/logging.h:703:
error: undefined reference to '__sanitizer_cov_trace_const_cmp2'

BUG=chromium:949338
TEST=libchrome buidls with coverage flags.

Change-Id: I79bc776eb152983bb54d122a307be8cfab7bbcba
Reviewed-on: https://chromium-review.googlesource.com/1551650
Commit-Ready: Manoj Gupta <manojgupta@chromium.org>
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 30afd10c1..fdc852846 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -31,8 +31,8 @@ config("libchrome_config") {
     "-Wno-unused-local-typedefs",
     "-Xclang-only=-Wno-char-subscripts",
   ]
-  # Address sanitizer builds do not support -z,defs.
-  if (!use.asan) {
+  # Address sanitizer + coverage builds do not support -z,defs.
+  if (!(use.asan || use.coverage)) {
     ldflags = [ "-Wl,-z,defs" ]
   }
 }