Revert 237900 "Add use_goma for GYP_DEFINES"

Broke the blink android build.
TBR=mkwst@chromium.org

> Add use_goma for GYP_DEFINES
> 
> If use_goma is specified in GYP_DEFINES, gomacc is automatically set as
> CC wrapper and CXX wrapper.  It uses the default goma directory if the gomadir
> option is not given.  No need to fix PATH when running ninja (or make).
> This is the revival of https://codereview.chromium.org/12419003/,
> and expected to work with https://codereview.chromium.org/66303010/.
> Note: Goma team suggest not to put gomadir in PATH if you use use_goma option.
> 
> Currently, this works well with ninja (default build system of chromium).
> It does not work well with make in some case (e.g. build on linux with make).
> 
> According to the review comment, ANDROID_GOMA_WRAPPER has already been
> obsoleted.  ANDROID_GOMA_WRAPPER will be just ignored after this change.
> 
> Example 1
> $ GYP_DEFINES="clang=1 use_goma=1" build/gyp_chromium
> (no need to set CC/CXX at this stage)
> 
> build.ninja will have
> cc = ${HOME}/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang
> cxx = ${HOME}/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++
> 
> The user can run ninja without setting PATH or so.
> $ ninja -C out/Release -j100
> 
> Example 2
> 
> $ GYP_DEFINES="use_goma=1 gomadir=/path/to/goma" build/gyp_chromium
> 
> build.ninja will have
> cc = /path/to/goma/gomacc gcc
> cxx = /path/to/goma/gomacc g++
> 
> user can run ninja without setting PATH or so.
> $ ninja -C out/Release -j100
> 
> BUG=173686
> 
> Review URL: https://codereview.chromium.org/69293004

TBR=yyanagisawa@chromium.org

Review URL: https://codereview.chromium.org/96703002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237911 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237911