Rationalize use_aura=1 and use_ash=1 on linux

BUG=236170
TEST=None
R=ben@chromium.org

Review URL: https://codereview.chromium.org/14554002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@197363 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

all.gyp

@@ -158,11 +158,15 @@
         }],
         ['use_aura==1', {
           'dependencies': [
-            '../ash/ash.gyp:*',
             '../ui/aura/aura.gyp:*',
             '../ui/oak/oak.gyp:*',
           ],
         }],
+        ['use_ash==1', {
+          'dependencies': [
+            '../ash/ash.gyp:*',
+          ],
+        }],
         ['remoting==1', {
           'dependencies': [
             '../remoting/remoting.gyp:*',