add comment to webkit_appcache.gypi for workaround to bug 105299.

TBR=tony@chromium.org
BUG=105299

Review URL: http://codereview.chromium.org/8677017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@111396 0039d316-1c4b-4281-b951-d872f2087c98

webkit/appcache/webkit_appcache.gypi

@@ -94,6 +94,7 @@
         }],
         [# TODO(dpranke): Figure out why this doesn't work outside of
          # a webkit build - this seems to be a bug in the make gyp generator.
+         # See http://code.google.com/p/chromium/issues/detail?id=105299 .
          'OS!="mac" and inside_chromium_build==1', {
           'dependencies': [
             '<(webkit_src_dir)/Source/WebKit/chromium/WebKit.gyp:webkit',