Do not exclude pdf from DEPS check.

Otherwise the DEPS file under pdf/ directory has no effect.

As a result of enabling it, some entries had to be added.

BUG=None
TEST=./tools/checkdeps/checkdeps.py - SUCCESS
R=thestig@chromium.org

Review URL: https://codereview.chromium.org/318763005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275148 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -578,7 +578,6 @@ skip_child_includes = [
   "metro_driver",
   "native_client_sdk",
   "o3d",
-  "pdf",
   "sdch",
   "skia",
   "testing",

pdf/DEPS

@@ -1,5 +1,9 @@
 include_rules = [
+  "!chrome/browser/chrome_page_zoom_constants.h",
+  "!chrome/common/content_restriction.h",
+  "!content/public/common/page_zoom.h",
   "+net",
   "+ppapi",
   "+third_party/pdfium/fpdfsdk/include",
+  "+ui/events/keycodes/keyboard_codes.h",
 ]