Update debugger GUI to have profile button & list widget to optionally display times

The profile action is currently stubbed out (following CLs will add functionality). 

The filename changes are so the filename will be around to be reloaded later for profiling.

[DerekS, 2012-11-12 20:12:07]

how are you planning on profiling?  The debugger's version of SkPicture is
wildly inefficient and isn't a good candidate for profiling results.

[robertphillips, 2012-11-12 20:18:08]

I have posted the entire debugger profiling CL so you can see all the working
parts. When the profile button is pressed the debugger basically fires up a
bench_pictures instance but installs a profiling picture playback class. The
picture playback class records the per-command times which are then fed back to
the debugger once it is complete.

[DerekS, 2012-11-12 20:26:35]

LGTM

[robertphillips, 2012-11-12 20:42:37]

committed as r6385