mac: Fix a memory leak in canvas_skia_mac.
mac: Fix a memory leak in canvas_skia_mac.

Found by the clang static analyzer:
ui/gfx/canvas_skia_mac.mm:70:27: warning: Potential leak of an object allocated on line 70 and stored into 'path'
  CGMutablePathRef path = CGPathCreateMutable();
                          ^
1 warning generated.

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/8308008

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@105751 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,ropik/chromium,gavinp/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,ropik/chromium,ropik/chromium,adobe/chromium,ropik/chromium,gavinp/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,yitian134/chromium,gavinp/chromium,ropik/chromium,gavinp/chromium,adobe/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,adobe/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,adobe/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium