Adds new libcast_media shared library for cast_shell media

chromecast/media/media.gyp

Index: chromecast/media/media.gyp
diff --git a/chromecast/media/media.gyp b/chromecast/media/media.gyp
index 7aa3d5ba06b5133e7e3cf2b79ebc39f37507977b..39c98c8a6a79efa3a9280f1129943d5864594be1 100644
--- a/chromecast/media/media.gyp
+++ b/chromecast/media/media.gyp
@@ -6,6 +6,8 @@
   'variables': {
     'chromium_code': 1,
     'chromecast_branding%': 'Chromium',
+    'enable_default_cast_media%': 1,

[lcwu1, 2015/05/13 01:58:24]

nit: I would probably change the gyp var name slightly to
"use_default_libcast_media' because we are talking about the default
implementation of the shared library here, not the default implementation of
cma. (The latter appears to suggest that way.)

[halliwell, 2015/05/13 03:43:33]

I think I was going for consistency with the graphics variable, but I see your
point.

Maybe the right fix is to change as you suggest, and change graphics to be
consistent with media?  The question never arose for graphics because there was
no cast_graphics target.

+    'libcast_media_gyp%': '',

[gunsch, 2015/05/13 03:26:04]

I just noticed libcast_graphics does the same thing, but I'm not sure I like
this approach.

For example, I assume we'll have prebuilt .so files that aren't provided via gyp
files. But this assumes there will always be a gyp target pointing to a target
that provides the .so file. Can we find a way to get rid of that assumption?

[halliwell, 2015/05/13 03:43:33]

We should discuss for sure.  The challenge is with Marvell, where we want to
supply a vendor override shared lib, but we also want to build it all in our
build system, unlike other vendors who might override the shared lib externally.

Last time around with graphics, we discussed having a make file step that copied
the Marvell so to replace the default one.  But we concluded that would be extra
complexity and that just depending on their gyp target makes sense for now.

   },
   'targets': [
     {
@@ -15,6 +17,7 @@
         '../../base/base.gyp:base',
         '../../crypto/crypto.gyp:crypto',
         '../../third_party/widevine/cdm/widevine_cdm.gyp:widevine_cdm_version_h',
+        '<(libcast_media_gyp):libcast_media_1.0',
       ],
       'sources': [
         'base/decrypt_context.cc',
@@ -294,5 +297,24 @@
         'cma/test/run_all_unittests.cc',
       ],
     },
+  ], # end of targets
+  'conditions': [
+    ['enable_default_cast_media==1', {
+      'targets': [
+        {
+          'target_name': 'libcast_media_1.0',
+          'type': 'shared_library',
+          'dependencies': [
+            '../../chromecast/chromecast.gyp:cast_public_api'
+          ],
+          'include_dirs': [
+            '../..',
+          ],
+          'sources': [
+            'base/cast_media_default.cc',
+          ],
+        }
+      ]
+    }],
   ],
 }