Lock the bitmap before calling getPixels().
Lock the bitmap before calling getPixels().

On calling getPixels() after decoding always return NULL as
SkBitmap fpixels is set to NULL while copying.

BUG=None
TEST=Existing

Review URL: https://codereview.chromium.org/1147803003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@195570 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk