Added Pdf to git ignore file.

BUG=none
TEST=none
NOTRY=TRUE

Review URL: https://chromiumcodereview.appspot.com/10807038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149214 0039d316-1c4b-4281-b951-d872f2087c98

.gitignore

@@ -110,6 +110,7 @@ v8.log
 /net/testserver.log
 /out
 /out_*
+/pdf
 /ppapi/native_client/nacl_irt.xml
 /ppapi/native_client/ppapi_lib.xml
 /ppapi/native_client/src/shared/ppapi_proxy/nacl_ppapi_browser.xml