Adding user doc section and core files for new site

site/user/quick/macos.md

+Mac OS X
+========
+
+Prerequisites
+-------------
+
+Make sure the following have been installed:
+
+  * XCode (Apple's development environment): required
+    * publicly available at http://developer.apple.com/xcode/
+    * add the optional Unix Tools to the install so you get the make command line tool.
+  * Chromium depot_tools: required to download the source and dependencies
+    * http://www.chromium.org/developers/how-tos/depottools
+
+Check out the source code
+-------------------------
+
+See the instructions [here](../download).
+
+Generate XCode projects
+-----------------------
+
+We use the open-source gyp tool to generate XCode projects (and analogous
+build scripts on other platforms) from our multiplatform "gyp" files.
+
+Before building, make sure that gyp knows to create an XCode project or ninja
+build files. If you leave GYP_GENERATORS undefined it will assume the
+following default:
+
+    GYP_GENERATORS="ninja,xcode"
+
+Or you can set it to `ninja` or `xcode` alone, if you like.
+
+You can then generate the Xcode projects and ninja build files by running:
+
+    ./gyp_skia
+
+Build and run tests from the command line
+-----------------------------------------
+
+    ninja -C out/Debug dm
+    out/Debug/dm
+
+The usual mode you want for testing is Debug mode (SK_DEBUG is defined, and
+debug symbols are included in the binary). If you would like to build the
+Release version instead:
+
+    ninja -C out/Release dm
+    out/Release/dm
+
+Build and run nanobench (performance tests)
+-------------------------------------------
+
+In this case, we will build with the "Release" configuration, since we are running performance tests.
+
+    ninja -C out/Release nanobench
+    out/Release/nanobench [ --skps path/to/*.skp ]
+
+Build and run SampleApp in the XCode IDE
+----------------------------------------
+
+  * Run gyp_skia as described above.
+  * In the Finder, navigate to $SKIA_INSTALLDIR/trunk/out/gyp
+  * Double-click SampleApp.xcodeproj ; this will launch XCode and open the SampleApp project
+  * Click the “Build and Run” button in the top toolbar
+  * Once the build is complete, you should see a window with lots of shaded text examples. To move through the sample app, use the following keypresses:
+    * right- and left-arrow keys: cycle through different test pages
+    * 'D' key: cycle through rendering methods for each test page
+    * other keys are defined in SampleApp.cpp’s SampleWindow::onHandleKey() and SampleWindow::onHandleChar() methods