Fix saving modified skp from debugger

This appears to work. In the old approach the deletion of the existing 'fPicture' also freed all the SkPaints (and other objects) that the 'fDebugCanvas' relied on. I believe this was so that the debugger would automatically "switch" to the modified skp. The current approach doesn't do this but it also doesn't crash.

[robertphillips, 2013-01-22 16:04:27]

This should address http://code.google.com/p/skia/issues/detail?id=998

[DerekS, 2013-01-22 16:44:27]

https://codereview.appspot.com/7181048/diff/1/debugger/SkDebugger.cpp
File debugger/SkDebugger.cpp (right):

https://codereview.appspot.com/7181048/diff/1/debugger/SkDebugger.cpp#newcode38
debugger/SkDebugger.cpp:38: SkPicture* newPicture = new SkPicture;
can we just clone the existing fPicture?

[robertphillips, 2013-01-22 17:52:43]

https://codereview.appspot.com/7181048/diff/1/debugger/SkDebugger.cpp
File debugger/SkDebugger.cpp (right):

https://codereview.appspot.com/7181048/diff/1/debugger/SkDebugger.cpp#newcode38
debugger/SkDebugger.cpp:38: SkPicture* newPicture = new SkPicture;
Unfortunately that doesn't respect the debugger's deletion flags. Replaying it
results in an skp with the deleted rows removed while cloning it leaves them in.

[DerekS, 2013-01-22 17:56:18]

lgtm

[robertphillips, 2013-01-22 18:04:41]

I added a comment to explain why clone isn't called in copyPicture.

committed as r7314