Update instructions.

Conflicts:
	README.md
Add xwalk path to git ignore list
Also need to set aura::Window title

Since each DesktopNativeWidgetAura uses a sole aura::Window as its
backed, once the title of native widget gets updated, the title of
aura::Window should also be updated in addition to updating the
XWindow created by DesktopRootWindowHostX11.

BUG=https://github.com/otcshare/crosswalk/issues/191
TEST=xwalk_browsertest --gtest_filter=XWalkRuntimeTest.GetWindowTitle
Aura: fix the touch event doesn't work on Tizen 3.0 issue.

Chromium uses the sourceid of a XIDeviceEvent to decide if it is orignated
from a touch device. See events_x.cc:717. However, Chromium uses deviceid to
check touch device. See touch_factory_x11.cc:158.

As X11 spec, only slave device has same sourceid and device id. So Chromium
should setup touch device list with XISlavePointer other than XIMasterPointer
device.

BUG=https://github.com/otcshare/crosswalk/issues/187
TESTS=https://github.com/borismus/MagicTouch/blob/master/samples/tracker.html
Export DesktopCursorLoaderUpdaterAuraX11 and DesktopFocusRules to maintain DesktopRootWindowHost inside xwalk.

We will perhaps make something like ui/views/widget/desktop_aura inside xwalk to
satisfy our all requirements. At that time, this patch can be rollbacked.
Fix touch support issue on Tizen 2.1

On Tizen 2.1, the multi-touch support is different from the XInput2.2
approach. It extends the older Input2.1 spec to use multiple touch
devices for multiple touch points, one touch device for one touch
points. The device type name for this purpose is MULTITOUCHSCREEN which
is not defined by XInput extension.

This fix is to make Crosswalk be able to handle the new extension to
XInput2.1 by introducing a new build option 'enable_xi21_mt'. It should
be turned on for Tizen 2.1, and is exclusive to 'use_xi2_mt' option.
Polish the comments for enable_xi21_mt usage.
Move ENABLE_XI21_MT definition to xwalk.

We don't want to change chromium sources if possible.
Fix the issue of video/audio playback with file://android_asset scheme.

The MediaPlayerBridge in Chromium accepts uri as data source, but MediaPlayer
can't handle file:///android_asset. So for such case, handle it specially.
[Android] Fix a set of rendering issues introduced by single process mode.

* There is browser side compositor in Android port, in single process mode. the
gl contexts in renderer will have race conditions with gl contexts in browser side.

* This issue leads to many rendering failes: (1) stop activity and then restart
will cause black screen; (2) Any page with compositing layers will leads to the
compositing layer black (WebGL. Canvas, Video).

* Fix this issue by duplicating the gl contexts implementation in browser side.

* This is a workaround fix for the critical blocking issue.

BUG=https://github.com/otcshare/crosswalk/issues/449, 430, 447, 455
[Tizen] Don't SetProcessTitleFromCommandLine.

SetProcessTitleFromCommandLine changes process title to absolute path of the
executable.

It has two issues on Tizen.
1. Tizen task manager can not recognize xwalk process.
2. Web app uses symbol link to the xwalk executable. Web app process title must
show symbol link path, not xwalk executable path for the task manager to
recognize Web app, not XWalk.
[Tizen] Change Sandbox IPC process title.

SetProcessTitleFromCommandLine() plays a role to change process title to
absolute path of the executable with arguments that the CommandLine object has.
For example, we want gpu process title to be "<xwalk dir>/xwalk
--type=gpu-process", not "/proc/self/exe --type=gpu-process"

However, we don't want to change browser process title, because browser process
title should be web app symbolic link path, not xwalk executable absolute path.

SandboxIPC process is the process forked by browser process. We want that
SandboxIPC process title is different from browser process title. Otherwise,
Tizen task switcher misunderstands that SandboxIPC process is also web
application process.

To achieve it,
1. Browser process must not call SetProcessTitleFromCommandLine();
2. Browser process must save argv pointer to change SandboxIPC process title later.
3. SandboxIPC process also calls SetProcessTitleFromCommandLine() to change its own process title.

BUG=https://github.com/crosswalk-project/crosswalk/issues/609
[Android] Extend android install timeout to 5 minutes for testing

For android trybots, they will use emulator to run tests.
On emulator, the operation will take really a lot of time.
[Android] When running android test, try killing adb if no devices found

It randomly happens that adb devices return empty list even device
is actually connected, killing adb and restart it can fix this.

CL=https://codereview.chromium.org/24194002