Documentation: Further cleanup

site/user/tips.md

Index: site/user/tips.md
diff --git a/site/user/tips.md b/site/user/tips.md
index 41536211e18b14a551f550adc7c1f43efc1ab617..ed701792dd6ded8ad794422ffad86ec095a3271a 100644
--- a/site/user/tips.md
+++ b/site/user/tips.md
@@ -1,12 +1,62 @@
 Tips & FAQ
 ==========
 
-Tips and Tricks
----------------
+<span id="gypdefines"></span>
+
+Gyp Options
+-----------
+
+When running `sync-and-gyp`, the `GYP_DEFINES` environment variable can
+be used to change Skia’s compile-time settings, using a
+space-separated list of key=value pairs. For example, to disable both
+the Skia GPU backend and PDF backends, run it as follows:
+
+<!--?prettify lang=sh?-->
+
+    GYP_DEFINES='skia_gpu=0 skia_pdf=0' python bin/sync-and-gyp
+    ninja -C out/Debug
+
+Note: Setting enviroment variables in the Windows CMD.EXE shell [uses a
+different syntax](/user/quick/windows#env).
+
+You can also set environment variables such as `CC`, `CXX`,
+`CFLAGS`, or `CPPFLAGS` to control how Skia is compiled. For
+example:
+
+<!--?prettify lang=sh?-->
+
+    CC='clang' CXX='clang++' python bin/sync-and-gyp
+    ninja -C out/Debug
+
+The `GYP_GENERATORS` environment variable can be used to set the
+build systems that you want to use (as a comma-separated list).
+The default is `'ninja,msvs-ninja'` on Windows, `'ninja,xcode'` on
+Mac OS X, and just `'ninja'` on Linux.  For example, to generate
+only Ninja files on Mac:
+
+<!--?prettify lang=sh?-->
+
+    GYP_GENERATORS='ninja' python bin/sync-and-gyp
+    ninja -C out/Debug
+
+Finally, the `SKIA_OUT` environment variable can be used to set
+the path for the build directory.  The default is `out` inside the
+top-level Skia source directory.  For example to test Skia with
+two different compilers:
+
+<!--?prettify lang=sh?-->
+
+    CC='clang' CXX='clang++' SKIA_OUT=~/build/skia_clang python bin/sync-and-gyp
+    CC='gcc'   CXX='g++'     SKIA_OUT=~/build/skia_gcc   python bin/sync-and-gyp
+    ninja -C ~/build/skia_clang/Debug
+    ninja -C ~/build/skia_gcc/Debug
+
+* * *
 
 <span id="bitmap-subsetting"></span>
 
-### Bitmap Subsetting
+Bitmap Subsetting
+-----------------
 
 Taking a subset of a bitmap is effectively free - no pixels are copied or
 memory is allocated. This allows Skia to offer an API that typically operates
@@ -22,8 +72,8 @@ drawBitmapNine():
 
 <span id="skp-capture"></span>
 
-### Capturing a `.skp` file on a web page in Chromium.
-
+Capture a `.skp` file on a web page in Chromium
+-----------------------------------------------
 
 1.  Launch Chrome or Chromium with `--no-sandbox --enable-gpu-benchmarking`
 2.  Open the JS console (ctrl-shift-J)
@@ -47,32 +97,32 @@ or use Skia's `SampleApp` to view it:
 
 * * *
 
-FAQ
----
-
 <span id="hw-acceleration"></span>
 
-### Does Skia support HW acceleration?
+How to add hardware acceleration in Skia
+----------------------------------------
 
-There are two ways Skia can take advantage of HW.
+There are two ways Skia takes advantage of specific hardware.
 
-1. Subclass SkCanvas
+1.  Subclass SkCanvas
 
-Since all drawing calls go through SkCanvas, those calls can be redirected to
-a different graphics API. SkGLCanvas has been written to direct its drawing
-calls to OpenGL. See src/gl/
+    Since all drawing calls go through SkCanvas, those calls can be
+    redirected to a different graphics API. SkGLCanvas has been
+    written to direct its drawing calls to OpenGL. See src/gl/
 
-2. Custom bottleneck routines
+2.  Custom bottleneck routines
 
-There are sets of bottleneck routines inside the blits of Skia that can be
-replace on a platform in order to take advantage of specific CPU features. One
-such example is the NEON SIMD instructions on ARM v7 devices. See src/opts/
+    There are sets of bottleneck routines inside the blits of Skia
+    that can be replace on a platform in order to take advantage of
+    specific CPU features. One such example is the NEON SIMD
+    instructions on ARM v7 devices. See src/opts/
 
 * * *
 
 <span id="font-hinting"></span>
 
-### Does Skia support Font hinting?
+Does Skia support Font hinting?
+-------------------------------
 
 Skia has a built-in font cache, but it does not know how to actual render font
 files like TrueType? into its cache. For that it relies on the platform to