Remove WTF from GN's root build.

I'm going ot make this target private to blink. Currently blink is brought into the build via other dependencies so this is no longer required.

R=jamesr@chromium.org
TBR=jamesr

Review URL: https://codereview.chromium.org/343993002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278415 0039d316-1c4b-4281-b951-d872f2087c98

BUILD.gn

@@ -83,8 +83,7 @@ group("root") {
     "//third_party/smhasher:murmurhash3",
     "//third_party/smhasher:pmurhash",
     "//third_party/speex",
-    "//third_party/WebKit/public:blink_headers",
-    "//third_party/WebKit/Source/wtf",
+    "//third_party/WebKit/public:all_blink",
     "//third_party/zlib",
     "//third_party:jpeg",
     "//tools/gn",
@@ -159,8 +158,7 @@ group("root") {
       "//third_party/flac",
 
       # TODO(brettw) make Blink work on Android.
-      "//third_party/WebKit/public:blink_headers",
-      "//third_party/WebKit/Source/wtf",
+      "//third_party/WebKit/public:all_blink",
 
       # Not tested on Android yet:
       "//webkit/browser:storage",