Temporary workaround to make VM bots greener.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index ba54d7dad0340cc7de594a6288194f33a0860a94..a61715bf5d0a573b253b6e85b330e6dd4f4874c3 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -77,6 +77,7 @@ const char* CanonicalFunction(const char* func) {
   }
 }
 
+#if 0
 #define API_TIMELINE_DURATION                                                  \
   TimelineDurationScope tds(Thread::Current(),                                 \
                             Timeline::GetVMApiStream(),                        \
@@ -86,6 +87,10 @@ const char* CanonicalFunction(const char* func) {
   TimelineBeginEndScope tbes(Thread::Current(),                                \
                              Timeline::GetVMApiStream(),                       \
                              CURRENT_FUNC)
+#else
+#define API_TIMELINE_DURATION ASSERT(true)
+#define API_TIMELINE_BEGIN_END ASSERT(true)
+#endif
 
 #if defined(DEBUG)
 // An object visitor which will iterate over all the function objects in the