Support higher CPU profiler sampling rate on posix systems

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 416 matching lines @@
 DEFINE_bool(always_full_compiler, false,
             "try to use the dedicated run-once backend for all code")
 DEFINE_int(max_opt_count, 10,
            "maximum number of optimization attempts before giving up.")
 
 // compilation-cache.cc
 DEFINE_bool(compilation_cache, true, "enable compilation cache")
 
 DEFINE_bool(cache_prototype_transitions, true, "cache prototype transitions")
 
+// cpu-profiler.cc
+#if defined(ANDROID)
+// Phones and tablets have processors that are much slower than desktop
+// and laptop computers for which current heuristics are tuned.
+#define DEFAULT_INTERVAL 5000
+#else
+#define DEFAULT_INTERVAL 1000
+#endif
+DEFINE_int(cpu_profiler_sampling_interval, DEFAULT_INTERVAL,
+           "CPU profiler sampling interval in microseconds")
+#undef DEFAULT_INTERVAL
+
 // debug.cc
 DEFINE_bool(trace_debug_json, false, "trace debugging JSON request/response")
 DEFINE_bool(trace_js_array_abuse, false,
             "trace out-of-bounds accesses to JS arrays")
 DEFINE_bool(trace_external_array_abuse, false,
             "trace out-of-bounds-accesses to external arrays")
 DEFINE_bool(trace_array_abuse, false,
             "trace out-of-bounds accesses to all arrays")
 DEFINE_implication(trace_array_abuse, trace_js_array_abuse)
 DEFINE_implication(trace_array_abuse, trace_external_array_abuse)
@@ skipping 364 matching lines @@
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 #undef DEFINE_implication
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS