Add Syzygy support to Windows GN build.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 41be865b44d8b5e5acbd7598b1ad330e36d865ef..2f13ace7465db5024bd9e176e0f1729458da237b 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -73,6 +73,7 @@ group("both_gn_and_gyp") {
     "//chrome/test:sync_integration_tests",
     "//chrome/test:unit_tests",
     "//chrome/test/chromedriver:chromedriver_unittests",
+    "//chrome/tools/build/win/syzygy:chrome_dll_syzygy",

[Dirk Pranke, 2015/07/20 19:29:41]

shouldn't this be under is_win or something?

[brettw, 2015/07/20 22:21:55]

I explicitly made the targets exist in all cases because the conditions where
these do something is rather complicated (not even all the time on Windows).

     "//components:components_browsertests",
     "//components:components_unittests",
     "//content/shell:content_shell",