Enable runtime checks for SSSE3 on x86 on Android.

Enable runtime checks for SSSE3 on x86 on Android.

$ compare-android.sh bench --match bitmap_ --repeat 30
master -> ssse3
N=30 p=0.001000 (corrected to 0.000033)
sig?  speedup  bench
  n    -1.16%  bitmap_scale_filter_256_64
  y    -0.72%  bitmap_8888_A_scale_bicubic
  y    -0.21%  bitmap_index8_A
  n    -0.00%  bitmap_565
  n    -0.00%  bitmap_scale_filter_90_80
  n     0.03%  bitmap_8888_A_source_transparent
  y     0.06%  bitmap_index8
  y     0.30%  bitmap_8888_A_source_stripes_two
  n     0.34%  bitmap_scale_filter_80_90
  y     0.42%  bitmap_8888_A
  y     0.44%  bitmap_8888_A_source_opaque
  n     0.53%  bitmap_scale_filter_90_10
  y     0.71%  bitmap_8888_A_source_stripes_three
  y     0.91%  bitmap_8888_A_scale_rotate_bicubic
  y     1.04%  bitmap_8888_update
  n     1.19%  bitmap_scale_filter_10_90
  n     1.39%  bitmap_scale_filter_90_90
  y     1.77%  bitmap_8888_update_volatile
  y     1.89%  bitmap_8888
  y     2.37%  bitmap_scale_filter_30_90
  y     9.57%  bitmap_scale_filter_64_256
  n    17.86%  bitmap_scale_filter_90_30
  y    25.40%  bitmap_8888_A_scale_rotate_bilerp
  y    27.19%  bitmap_8888_scale_rotate_bilerp
  y    27.23%  bitmap_8888_update_scale_rotate_bilerp
  y    27.29%  bitmap_8888_update_volatile_scale_rotate_bilerp
  y    55.08%  bitmap_8888_A_scale_bilerp
  y    58.75%  bitmap_8888_update_volatile_scale_bilerp
  y    58.90%  bitmap_8888_scale_bilerp
  y    58.92%  bitmap_8888_update_scale_bilerp
Overall speedup: 10.52%

BUG=skia:1111
R=djsollen@google.com

Committed: https://code.google.com/p/skia/source/detail?r=10474

[mtklein, 2013-07-30 18:52:34]

So far so good.  Testing on razr i trybot too.

[djsollen, 2013-07-31 12:33:42]

lgtm

[mtklein, 2013-07-31 20:09:28]

Committed patchset #1 manually as r10474 (presubmit successful).