Reduce signal sender thread stack size to 32k.

src/platform-macos.cc

Index: src/platform-macos.cc
===================================================================
--- src/platform-macos.cc	(revision 10368)
+++ src/platform-macos.cc	(working copy)
@@ -75,7 +75,7 @@
 namespace v8 {
 namespace internal {
 
-// 0 is never a valid thread id on MacOSX since a ptread_t is
+// 0 is never a valid thread id on MacOSX since a pthread_t is
 // a pointer.
 static const pthread_t kNoThread = (pthread_t) 0;
 
@@ -103,7 +103,7 @@
 
 // We keep the lowest and highest addresses mapped as a quick way of
 // determining that pointers are outside the heap (used mostly in assertions
-// and verification).  The estimate is conservative, ie, not all addresses in
+// and verification).  The estimate is conservative, i.e., not all addresses in
 // 'allocated' space are actually allocated to our heap.  The range is
 // [lowest, highest), inclusive on the low and and exclusive on the high end.
 static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
@@ -473,20 +473,14 @@
   pthread_t thread_;  // Thread handle for pthread.
 };
 
+
 Thread::Thread(const Options& options)
     : data_(new PlatformData),
-      stack_size_(options.stack_size) {
-  set_name(options.name);
+      stack_size_(options.stack_size()) {
+  set_name(options.name());
 }
 
 
-Thread::Thread(const char* name)
-    : data_(new PlatformData),
-      stack_size_(0) {
-  set_name(name);
-}
-
-
 Thread::~Thread() {
   delete data_;
 }
@@ -736,10 +730,13 @@
   thread_act_t profiled_thread_;
 };
 
+
 class SamplerThread : public Thread {
  public:
+  static const int kSamplerThreadStackSize = 32 * KB;
+
   explicit SamplerThread(int interval)
-      : Thread("SamplerThread"),
+      : Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)),
         interval_(interval) {}
 
   static void AddActiveSampler(Sampler* sampler) {