1. Add flag --trace-api to trace API function invocation

runtime/vm/native_arguments.h

Index: runtime/vm/native_arguments.h
===================================================================
--- runtime/vm/native_arguments.h	(revision 27137)
+++ runtime/vm/native_arguments.h	(working copy)
@@ -48,9 +48,9 @@
     VerifyPointersVisitor::VerifyPointers();                                   \
     Isolate::Current()->heap()->Verify();                                      \
   }
-#define TRACE_NATIVES(name)                                                    \
+#define TRACE_NATIVES(format, name)                                            \

[regis, 2013/09/04 23:05:15]

TRACE_NATIVE_CALL for symmetry with TRACE_API_CALL?
OK, the flags are not symmetric.

[siva, 2013/09/04 23:27:42]

Changed the name to TRACE_NATIVE_CALL

On 2013/09/04 23:05:15, regis wrote:

   if (FLAG_trace_natives) {                                                    \
-    OS::Print("Calling native: %s\n", name);                                   \
+    OS::Print("Calling native: " format "\n", name);                           \
   }
 #define DEOPTIMIZE_ALOT                                                        \
   if (FLAG_deoptimize_alot) {                                                  \
@@ -61,7 +61,7 @@
 
 #define CHECK_STACK_ALIGNMENT { }
 #define VERIFY_ON_TRANSITION { }
-#define TRACE_NATIVES(name) { }
+#define TRACE_NATIVES(format, name) { }
 #define DEOPTIMIZE_ALOT { }
 
 #endif