[spelling] existance to existence

native_client_sdk/src/tools/common.mk

 # 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.
 
 #
 # GNU Make based build file.  For details on GNU Make see:
 #   http://www.gnu.org/software/make/manual/make.html
 #
 
 #
@@ skipping 256 matching lines @@
         $(RM) -f $(TARGET).nmf
         $(RM) -rf $(OUTDIR)
         $(RM) -rf user-data-dir
 
 
 #
 # Rules for output directories.
 #
 # Output will be places in a directory name based on Toolchain and configuration
 # be default this will be "newlib/Debug".  We use a python wrapped MKDIR to
-# proivde a cross platform solution. The use of '|' checks for existance instead
+# proivde a cross platform solution. The use of '|' checks for existence instead
 # of timestamp, since the directory can update when files change.
 #
 %dir.stamp :
         $(MKDIR) -p $(dir $@)
         @echo Directory Stamp > $@
 
 
 #
 # Dependency Macro
 #
@@ skipping 249 matching lines @@
 # uppercase aliases (for backward compatibility)
 .PHONY: CHECK_FOR_CHROME DEBUG LAUNCH RUN
 CHECK_FOR_CHROME: check_for_chrome
 DEBUG: debug
 LAUNCH: run
 RUN: run
 
 endif  # TOOLCHAIN is valid...
 
 endif  # TOOLCHAIN=all