Only run GYP for Windows targets on Windows

This prevents GYP from running on macOS, where it would produce a bunch
of pointless .xcodeproj directories for Windows libraries and tools that
could never possibly build. Those would pollute “git status” output and
other operations.

Check in a new default.xml generated from DEPS too. It doesn’t
correspond to this change, but I should have done this in 26b988681d.

Change-Id: I034a5b30d13fdcc14911fc1354504375752d6144
Reviewed-on: https://chromium-review.googlesource.com/688045
Reviewed-by: Robert Sesek <rsesek@chromium.org>

DEPS

@@ -55,6 +55,15 @@ deps = {
 }
 
 hooks = [
+  {
+    # Keep the manifest up to date.
+    "action": ["python", "src/src/tools/python/deps-to-manifest.py",
+               "src/DEPS", "src/default.xml"],
+  },
+]
+
+hooks_os = {
+  'win': [
     {
       # TODO(chrisha): Fix the GYP files so that they work without
       # --no-circular-check.
@@ -71,9 +80,5 @@ hooks = [
                  "--no-circular-check",
                  "src/src/tools/windows/tools_windows.gyp"],
     },
-  {
-    # Keep the manifest up to date.
-    "action": ["python", "src/src/tools/python/deps-to-manifest.py",
-               "src/DEPS", "src/default.xml"],
-  },
-]
+  ],
+}

default.xml

@@ -22,7 +22,7 @@
 
   <project path='src/src/tools/gyp'
            name='external/gyp/'
-           revision='e8ab0833a42691cd2184bd4c45d779e43821d3e0'
+           revision='324dd166b7c0b39d513026fa52d6280ac6d56770'
            remote='chromium' />
 
   <project path='src/src/testing'