Make gyp a Windows-only dependency.

BUG=pdfium:559

Change-Id: Id0a01bcc2de597ce2b2e3d60dd5c737af75c93ab
Reviewed-on: https://pdfium-review.googlesource.com/2958
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/DEPS b/DEPS
index e2c33b7..eaf1082 100644
--- a/DEPS
+++ b/DEPS
@@ -58,10 +58,6 @@
     Var('chromium_git') + "/chromium/src/tools/generate_library_loader@" +
         Var('gen_library_loader_revision'),
 
-  # TODO(GYP): Remove this when no tools rely on GYP anymore.
-  "tools/gyp":
-    Var('chromium_git') + '/external/gyp.git' + '@' + 'c61b0b35c8396bfd59efc6cfc11401d912b0f510',
-
   "tools/memory":
     Var('chromium_git') + "/chromium/src/tools/memory@" +
         Var('tools_memory_revision'),
@@ -78,6 +74,10 @@
       Var('chromium_git') + "/external/github.com/catapult-project/catapult.git@" + Var('catapult_revision'),
   },
   "win": {
+    # TODO(GYP): Remove this when no tools rely on GYP anymore.
+    "tools/gyp":
+      Var('chromium_git') + '/external/gyp.git' + '@' + 'c61b0b35c8396bfd59efc6cfc11401d912b0f510',
+
     "v8/third_party/cygwin":
       Var('chromium_git') + "/chromium/deps/cygwin@" + Var('cygwin_revision'),
   },