Get printing working in Aura.

printing/printing.gyp

Index: printing/printing.gyp
diff --git a/printing/printing.gyp b/printing/printing.gyp
index ca7f7879cb238ba8432808a9fcf6064eb30312a1..5cac6075809e0c9b729ee3fdc4621b293c03990c 100644
--- a/printing/printing.gyp
+++ b/printing/printing.gyp
@@ -66,9 +66,6 @@
         'printed_pages_source.h',
         'printing_context.cc',
         'printing_context.h',
-        'printing_context_aura.cc',
-        'printing_context_cairo.cc',
-        'printing_context_cairo.h',
         'printing_context_mac.mm',
         'printing_context_mac.h',
         'printing_context_win.cc',
@@ -123,7 +120,6 @@
               'sources!': [
                 'image_aura.cc',
                 'printed_document_aura.cc',
-                'printing_context_aura.cc',
               ],
             }],
           ],
@@ -138,6 +134,12 @@
             'backend/print_backend_win.cc',
           ],
         }],
+        ['chromeos==1 or use_aura==1',{
+          'sources': [
+            'printing_context_no_system_dialog.cc',
+            'printing_context_no_system_dialog.h',
+          ],
+        }],
         ['use_cups==1', {
           'dependencies': [
             'cups',
@@ -170,6 +172,12 @@
             'backend/print_backend_chromeos.cc',
           ],
         }],
+        ['OS=="linux" and chromeos==0', {
+          'sources': [
+            'printing_context_gtk.cc',
+            'printing_context_gtk.h',
+          ],
+        }],
       ],
     },
     {
@@ -194,13 +202,9 @@
         'units_unittest.cc',
       ],
       'conditions': [
-        ['toolkit_uses_gtk == 0', {'sources/': [['exclude', '_cairo_unittest\\.cc$']]}],
+        ['toolkit_uses_gtk == 0', {'sources/': [['exclude', '_gtk_unittest\\.cc$']]}],
         ['OS!="mac"', {'sources/': [['exclude', '_mac_unittest\\.(cc|mm?)$']]}],
-        ['OS!="win"', {'sources/': [['exclude', '_win_unittest\\.cc$']]
-          }, {  # else: OS=="win"
-            'sources/': [['exclude', '_cairo_unittest\\.cc$']]
-          }
-        ],
+        ['OS!="win"', {'sources/': [['exclude', '_win_unittest\\.cc$']]}],
         ['toolkit_uses_gtk == 1', {
           'dependencies': [
             '../build/linux/system.gyp:gtk',