docs: fix 'compliation' typo in mac_build_instructions.md

docs/mac_build_instructions.md

 # Mac Build Instructions
 
 [TOC]
 
 ## Prerequisites
 
 *   A Mac running 10.9+.
 *   [Xcode](https://developer.apple.com/xcode), 5+.
 *   Install
     [gclient](http://dev.chromium.org/developers/how-tos/install-depot-tools),
@@ skipping 118 matching lines @@
 
 ## Contributing
 
 Once you’re comfortable with building Chromium, check out
 [Contributing Code](http://dev.chromium.org/developers/contributing-code) for
 information about writing code for Chromium and contributing it.
 
 ## Using Xcode-Ninja Hybrid
 
 While using Xcode is unsupported, GYP supports a hybrid approach of using ninja
-for building, but Xcode for editing and driving compliation.  Xcode can still be
+for building, but Xcode for editing and driving compilation. Xcode can still be
 slow, but it runs fairly well even **with indexing enabled**.
 
 With hybrid builds, compilation is still handled by ninja, and can be run by the
 command line (e.g. ninja -C out/Debug chrome) or by choosing the chrome target
 in the hybrid workspace and choosing build.
 
 To use Xcode-Ninja Hybrid, set `GYP_GENERATORS=ninja,xcode-ninja`.
 
 Due to the way Xcode parses ninja output paths, it's also necessary to change
 the main gyp location to anything two directories deep. Otherwise Xcode build
@@ skipping 76 matching lines @@
 be set in `/etc/sysctl.conf`:
 
     echo kern.maxvnodes=$((512*1024)) | sudo tee -a /etc/sysctl.conf
 
 Or edit the file directly.
 
 If your `git --version` reports 2.6 or higher, the following may also improve
 performance of `git status`:
 
     git update-index --untracked-cache