[NaCl SDK] A bunch of spelling fixes.

native_client_sdk/src/examples/pi_generator/pi_generator.cc

 // Copyright (c) 2012 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 <stdio.h>
 #include <stdlib.h>
 #include <cassert>
 #include <cmath>
 #include <cstring>
 #include <string>
@@ skipping 16 matching lines @@
 // This is called by the browser when the 2D context has been flushed to the
 // browser window.
 void FlushCallback(void* data, int32_t result) {
   static_cast<pi_generator::PiGenerator*>(data)->set_flush_pending(false);
 }
 
 }  // namespace
 
 namespace pi_generator {
 
-// A small helper RAII class that implementes a scoped pthread_mutex lock.
+// A small helper RAII class that implements a scoped pthread_mutex lock.
 class ScopedMutexLock {
  public:
   explicit ScopedMutexLock(pthread_mutex_t* mutex) : mutex_(mutex) {
     if (pthread_mutex_lock(mutex_) != kPthreadMutexSuccess) {
       mutex_ = NULL;
     }
   }
   ~ScopedMutexLock() {
     if (mutex_)
       pthread_mutex_unlock(mutex_);
@@ skipping 185 matching lines @@
       // Set color to red.
       color += 4 << kRedShift;
       color &= kRedMask;
     }
     pixel_bits[pi_generator->width() * py + px] = color | kOpaqueColorMask;
   }
   return 0;
 }
 
 }  // namespace pi_generator