Change default to not use pthreads at startup (all calculations on main thread)

native_client_sdk/src/examples/demo/voronoi/voronoi.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <assert.h>
 #include <math.h>
 #include <ppapi/cpp/completion_callback.h>
 #include <ppapi/cpp/graphics_2d.h>
 #include <ppapi/cpp/image_data.h>
 #include <ppapi/cpp/input_event.h>
@@ skipping 183 matching lines @@
   width_ = 0;
   height_ = 0;
   stride_in_pixels_ = 0;
   pixel_buffer_ = NULL;
   benchmark_frame_counter_ = 0;
   benchmarking_ = false;
 
   point_count_ = kStartPointCount;
   Reset();
 
-  // By default, do single threaded rendering.
-  num_threads_ = 1;
+  // By default, render from the dispatch thread.
+  num_threads_ = 0;
   workers_ = new ThreadPool(num_threads_);
 
   // Request PPAPI input events for mouse & keyboard.
   RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE);
   RequestInputEvents(PP_INPUTEVENT_CLASS_KEYBOARD);
 }
 
 Voronoi::~Voronoi() {
   delete workers_;
   DestroyContext();
@@ skipping 357 matching lines @@
     return new Voronoi(instance);
   }
 };
 
 namespace pp {
 Module* CreateModule() {
   return new VoronoiModule();
 }
 }  // namespace pp