Update Android toolchain to NDK r8d with GCC 4.7

Update Android toolchain to NDK r8d with GCC 4.7

Committed: https://code.google.com/p/skia/source/detail?r=7343

[EricB, 2013-01-23 16:22:26]

https://codereview.appspot.com/7201045/diff/1/gyp/common_conditions.gypi
File gyp/common_conditions.gypi (right):

https://codereview.appspot.com/7201045/diff/1/gyp/common_conditions.gypi#newc...
gyp/common_conditions.gypi:341: '-march=armv7-a',
This flag is already defined.  Should it be removed here?

[DerekS, 2013-01-23 16:41:59]

https://codereview.appspot.com/7201045/diff/1/gyp/common_conditions.gypi
File gyp/common_conditions.gypi (right):

https://codereview.appspot.com/7201045/diff/1/gyp/common_conditions.gypi#newc...
gyp/common_conditions.gypi:341: '-march=armv7-a',
On 2013/01/23 16:22:26, EricB wrote:
> This flag is already defined.  Should it be removed here?

This is a cflags and the other is an ldflags

[EricB, 2013-01-23 18:20:36]

https://codereview.appspot.com/7201045/diff/1/gyp/common_conditions.gypi
File gyp/common_conditions.gypi (right):

https://codereview.appspot.com/7201045/diff/1/gyp/common_conditions.gypi#newc...
gyp/common_conditions.gypi:341: '-march=armv7-a',
On 2013/01/23 16:41:59, DerekS wrote:
> On 2013/01/23 16:22:26, EricB wrote:
> > This flag is already defined.  Should it be removed here?
> 
> This is a cflags and the other is an ldflags

Whoops, missed that.  Still, this is independent of arm_neon, whereas the other
is only on with arm_neon==1.  Is that intended?

[DerekS, 2013-01-23 18:23:34]

Yes it is intended, based on the following NDK docs...

If you want to use Neon instructions, you will need to change the -mfpu
compiler flag:

  CFLAGS='-march=armv7-a -mfloat-abi=softfp -mfpu=neon'

Note that this forces the use of VFPv3-D32, as per the ARM specification.

Also, make sure the following two flags are provided to linker:

  LDFLAGS='-march=armv7-a -Wl,--fix-cortex-a8'

[EricB, 2013-01-23 18:26:56]

LGTM