Fix spelling mistakes in //docs.

docs/cr_user_manual.md

 # Cr
 
 Cr is a tool that tries to hide some of the tools used for working on Chromium
 behind an abstraction layer. Nothing that cr does can't be done manually, but cr
 attempts to make things nicer. Its main additional feature is that it allows you
 to build many configurations and run targets within a single checkout (by not
 relying on a directory called 'out'). This is especially important when you want
-to cross-compile (for instance, building android from linux or building arm from
+to cross-compile (for instance, building Android from Linux or building arm from
 intel), but it extends to any build variation.
 
 [TOC]
 
 ## A quick example
 
 The following is all you need to prepare an output directory, and then build and
 run the release build of chrome for the host platform:
 
 ```shell
@@ skipping 26 matching lines @@
 It should be mostly self documenting
 
     cr --help
 
 will list all the commands installed
 
     cr --help command
 
 will give you more detailed help for a specific command.
 
-_**A note to existing android developers:**_
+_**A note to existing Android developers:**_
 
 *   Do not source envsetup! ever!
 *   If you use cr in a shell that has had envsetup sourced, miscellaneous things
     will be broken. The cr tool does all the work that envsetup used to do in a
     way that does not pollute your current shell.
 *   If you really need a shell that has had the environment modified like
     envsetup used to do, see the cr shell command, also probably file a bug for
     a missing cr feature!
 
 ## The commands
@@ skipping 20 matching lines @@
 
 ### Build commands
 
     build
 
 Build a target.
 
     install
 
 Install a binary. Does build first unless `--builder==skip`. This does nothing
-on linux, and installs the apk onto the device for android builds.
+on Linux, and installs the apk onto the device for Android builds.
 
     run
 
 Invoke a target. Does an install first, unless `--installer=skip`.
 
     debug
 
 Debug a target. Does a run first, unless `--runner=skip`. Uses the debugger
 specified by `--debugger`.
 
 ### Other commands
 
     sync
 
 Sync the source tree. Uses gclient sync to do the real work.
 
     shell
 
 Run an exernal command in a cr environment. This is an escape hatch, if passed
 a command it runs it in the correct environment for the current output
 directory, otherwise it starts a sub shell with that environment. This allows
 you to run any commands that don't have shims, or are too specialized to get
-one. This is especially important on android where the environment is heavily
+one. This is especially important on Android where the environment is heavily
 modified.
 
 ## Preparing to build
 
 The first thing you need to do is prepare an output directory to build into.
 You do this with:
 
     cr init
 
-By default on linux this will prepare a linux x86 release build output
-directory, called `out_linux/Release`, if you want an android debug one, you can
+By default on Linux this will prepare a Linux x86 release build output
+directory, called `out_linux/Release`, if you want an Android debug one, you can
 use:
 
     cr init --out=out_android/Debug
 
 The output directory can be called anything you like, but if you pick a non
 standard name cr might not be able to infer the platform, in which case you need
 to specify it. The second part **must** be either Release or Debug. All options
 can be shortened to the shortest non ambiguous prefix, so the short command line
-to prepare an android debug output directory in out is:
+to prepare an Android debug output directory in out is:
 
     cr init --o=out/Debug --p=android
 
 It is totally safe to do this in an existing output directory, and is an easy
 way to migrate an existing output directory to use in cr if you don't want to
 start from scratch.
 
 Most commands in cr take a --out parameter to tell them which output directory
 you want to operate on, but it will default to the last value passed to init or
 select. This enables you to omit it from most commands.
@@ skipping 52 matching lines @@
 ## Known issues
 
 You can see the full list of issues with
 [this](https://code.google.com/p/chromium/issues/list?can=2&q=label%3Atool-cr)
 query, but here are the high level issues:
 
 *   **Only supports gtest** : You run tests using the run command, which tries
     to infer from the target whether it is a runnable binary or a test. The
     inference could be improved, and it needs to handle the other test types as
     well.
-*   **No support for windows or mac** : allowed for in the design, but need
+*   **No support for Windows or Mac** : allowed for in the design, but need
     people with expertise on those platforms to help out
 *   **Bash completion** : The hooks for it are there, but at the moment it only
     ever completes the command, not any of the arguments
 
 [Report a bug]:
 https://code.google.com/p/chromium/issues/entry?comment=%3CDont%20forget%20to%20attach%20the%20command%20lines%20used%20with%20-v=4%20if%20possible%3E&pri=2&labels=OS-Android,tool-cr,Build-Tools,Type-Bug&owner=iancottrell@chromium.org&status=Assigned