Coverity: Add a default case in SkPDFShader. CID=101159
Coverity: Add a default case in SkPDFShader. CID=101159

Code from thestig@chromium.org original CL: http://codereview.appspot.com/5498052/

Review URL: http://codereview.appspot.com/5502052

git-svn-id: e8541e15acce502a64c929015570ad1648e548cd@2913 2bbb7eff-a529-9590-31e7-b0007b416f81

MatChung/color-emoji.skia,hbwhlklive/color-emoji.skia,MatChung/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,Frankie-666/color-emoji.skia,Frankie-666/color-emoji.skia,Frankie-666/color-emoji.skia,Hankuo/color-emoji.skia,MatChung/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,hbwhlklive/color-emoji.skia,MatChung/color-emoji.skia,Frankie-666/color-emoji.skia,MatChung/color-emoji.skia,hbwhlklive/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,Frankie-666/color-emoji.skia,Frankie-666/color-emoji.skia,Hankuo/color-emoji.skia,MatChung/color-emoji.skia,Hankuo/color-emoji.skia