Add ENABLE_PRINTING and disable it on Android.

chrome/chrome_tests.gypi

Index: chrome/chrome_tests.gypi
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 185a5b32d4194f18a5a9ce31212f7a0f6bc272b0..333275c6477b7ae716e7f6a6cf66ce57276f19c7 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -2117,6 +2117,12 @@
             ['exclude', '^browser/automation/'],
           ],
         }],
+        ['enable_printing!=1', {
+          'sources/': [
+            ['exclude', '^browser/printing/'],
+            ['exclude', '^browser/ui/webui/print_preview/'],
+          ],
+        }],
         ['enable_session_service!=1', {
           'sources!': [
             'browser/sessions/session_service_unittest.cc',
@@ -2377,14 +2383,12 @@
           'sources/': [
             ['exclude', '^browser/captive_portal/'],
             ['exclude', '^browser/chrome_to_mobile'],
-            ['exclude', '^browser/printing/'],
             ['exclude', '^browser/themes/'],
             ['exclude', '^browser/ui/panels'],
             ['exclude', '^browser/ui/tabs/'],
             ['exclude', '^browser/ui/toolbar/'],
             ['exclude', '^browser/ui/webui/options/'],
             ['exclude', '^browser/ui/webui/options2/'],
-            ['exclude', '^browser/ui/webui/print_preview/'],
             # No service process on Android.
             ['exclude', '^common/service_'],
             ['exclude', '^service/'],