Fix typo in the official build target

Review URL: http://codereview.chromium.org/5905002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@69288 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

all.gyp

@@ -402,7 +402,7 @@
                 '../courgette/courgette.gyp:courgette',
                 '../pdf/pdf.gyp:pdf',
                 '../third_party/adobe/flash/flash_player.gyp:flash_player',
-                '../webkit/webkit.gyp:test_shell.gyp',
+                '../webkit/webkit.gyp:test_shell',
               ],
             },
           ], # targets