Don't globally define HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC

It's used only in a single file, so define it there
(condition_variable_posix.cc).

Bug: None
Change-Id: Ia59b42486feee2920f77dbcbef40a0d801bd2b51
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2405416
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806374}

base/synchronization/condition_variable_posix.cc

@@ -15,6 +15,10 @@
 #include "base/time/time.h"
 #include "build/build_config.h"
 
+#if defined(OS_ANDROID) && __ANDROID_API__ < 21
+#define HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC 1
+#endif
+
 namespace base {
 
 ConditionVariable::ConditionVariable(Lock* user_lock)
@@ -31,7 +35,7 @@ ConditionVariable::ConditionVariable(Lock* user_lock)
   // versions have pthread_condattr_setclock.
   // Mac can use relative time deadlines.
 #if !defined(OS_APPLE) && !defined(OS_NACL) && \
-    !(defined(OS_ANDROID) && defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC))
+    !defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC)
   pthread_condattr_t attrs;
   rv = pthread_condattr_init(&attrs);
   DCHECK_EQ(0, rv);
@@ -120,12 +124,12 @@ void ConditionVariable::TimedWait(const TimeDelta& max_time) {
   absolute_time.tv_nsec %= Time::kNanosecondsPerSecond;
   DCHECK_GE(absolute_time.tv_sec, now.tv_sec);  // Overflow paranoia
 
-#if defined(OS_ANDROID) && defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC)
+#if defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC)
   int rv = pthread_cond_timedwait_monotonic_np(
       &condition_, user_mutex_, &absolute_time);
 #else
   int rv = pthread_cond_timedwait(&condition_, user_mutex_, &absolute_time);
-#endif  // OS_ANDROID && HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC
+#endif  // HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC
 #endif  // OS_APPLE
 
   // On failure, we only expect the CV to timeout. Any other error value means

build/config/android/BUILD.gn

@@ -80,13 +80,6 @@ config("compiler") {
   cflags += [ "--target=$abi_target$compile_api_level" ]
   ldflags += [ "--target=$abi_target$compile_api_level" ]
 
-  # TODO(crbug.com/771171): Remove this define once code that uses it has been
-  # updated to no longer need it. This is leftover from older Android NDK
-  # versions.
-  if (compile_api_level < 21) {
-    cflags += [ "-DHAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC=1" ]
-  }
-
   # Assign any flags set for the C compiler to asmflags so that they are sent
   # to the assembler.
   asmflags = cflags