[NaCl SDK] A bunch of spelling fixes.

native_client_sdk/src/examples/file_histogram/file_histogram.cc

Index: native_client_sdk/src/examples/file_histogram/file_histogram.cc
diff --git a/native_client_sdk/src/examples/file_histogram/file_histogram.cc b/native_client_sdk/src/examples/file_histogram/file_histogram.cc
index 26d4b193baeacc2fac97e91aaaa302c5f5f0eb40..ea8c8e0a5cb4d6aee90c74b47875ff50d16cabc4 100644
--- a/native_client_sdk/src/examples/file_histogram/file_histogram.cc
+++ b/native_client_sdk/src/examples/file_histogram/file_histogram.cc
@@ -57,7 +57,7 @@ const size_t kHistogramSize = 256u;
 
 /// The Instance class.  One of these exists for each instance of your NaCl
 /// module on the web page.  The browser will ask the Module object to create
-/// a new Instance for each occurence of the <embed> tag that has these
+/// a new Instance for each occurrence of the <embed> tag that has these
 /// attributes:
 ///     type="application/x-nacl"
 ///     src="file_histogram.nmf"