bookmarks: Minor cleanup: Move PrunuInvisibleFolders() into unnamed namespace.

There is already a unnamed namespace at the top of the file with a bunch
of other helper functions so it makes more sense to group
PruneInvisibleFolders() along with them.

BUG=None
TEST=None, no functional changes.
R=sky@chromium.org

Review URL: https://codereview.chromium.org/102933002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238629 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238629
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/69293004/.
In https://codereview.chromium.org/69293004/, I removed ANDROID_GOMA_WRAPPER
code, which is actually used.  This code supports both way of enabling goma
for Android.  You can set GOMA_DIR or you can set -D use_goma=1.

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).

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
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=237900

Review URL: https://codereview.chromium.org/96923002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238630 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238630