Fix perf regression in Color32.

The regression was due to the fact that we were calling PlatformColorProc() for
every span (which in turns makes CPUID, a fairly expensive call).  Since we draw
a lot of rects, and rects have 1-pixel wide spans for the vertical segments,
that's a lot of CPUID.

Fixed by cacheing the result of PlatformColorProc(), as is done for the other
platform-specific blitters.

Review URL:  http://codereview.appspot.com/3669042/



git-svn-id: http://skia.googlecode.com/svn/trunk@636 2bbb7eff-a529-9590-31e7-b0007b416f81
6 files changed