ANDROID_EMU_ASYNC_SWAP extension searching + setting

In order for the async frame swapping feature to work
with all combinations of new/old emulators and system images,
one way to do it is to introduce an emulator-specific GL
extension. This is the same way the checksum calculation
support works.

This is a port to device/generic/goldfish-opengl, based on

https://googleplex-android-review.git.corp.google.com/#/c/1065345/

This is part of a sequential, multi-CL change. There is also
a corresponding multi-CL change on the host side:

https://android-review.googlesource.com/#/q/topic:emu-glsync-host

The changes in the system image are as follows:

platform/build:

https://googleplex-android-review.git.corp.google.com/1024926

device/generic/goldfish:

https://googleplex-android-review.git.corp.google.com/1230942

device/generic/goldfish-opengl:

https://googleplex-android-review.git.corp.google.com/1219535 <- this CL
https://googleplex-android-review.git.corp.google.com/1219536
https://googleplex-android-review.git.corp.google.com/1219537
https://googleplex-android-review.git.corp.google.com/1219538
https://googleplex-android-review.git.corp.google.com/1219539
https://googleplex-android-review.git.corp.google.com/1219570
https://googleplex-android-review.git.corp.google.com/1219571

Change-Id: Id07a72e5cb3397ff9d0b55788b8ad763c15050f3
4 files changed
tree: fc78732a5c03df2af9a0c6014862d90c2613bf08
  1. host/
  2. shared/
  3. system/
  4. tests/
  5. Android.mk
  6. common.mk
  7. README