Adds PrintingContext implementation stub for Android.

printing/printing.gyp

Index: printing/printing.gyp
diff --git a/printing/printing.gyp b/printing/printing.gyp
index b3bbf2b04bb8fa29de50d3f71f37b375311b8308..234facfb29ca950a3d8075ae55cdd0689f984787 100644
--- a/printing/printing.gyp
+++ b/printing/printing.gyp
@@ -228,6 +228,11 @@
             'printing_context_gtk.h',
           ],
         }],
+        ['OS=="android"', {
+          'sources': [
+            'printing_context_android.h',

[Lei Zhang, 2013/08/13 23:26:37]

No printing_context_android.cc? How does that work?

[whywhat, 2013/08/13 23:38:48]

We figured that printing will not be compiled for Android without the private
repo (e.g. TestShell doesn't use printing). So we have a header in the public
repo but the .cc file is in the private repo. This is already used for
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...
for example.

Otherwise we'd have to provide a dummy implementation and some run-time hook
(like with MediaPlayerManager,
https://code.google.com/p/chromium/codesearch#chromium/src/media/base/android...)
to override the dummy implementation if the private repo is present.

Unfortunately, GYP can't replace .cc file based on whether we have the private
repo or not AFAIK.

+          ],
+        }],
       ],
     },
     {