Clean up V4L2 codec-related flags and defines

content/common/common.gni

Index: content/common/common.gni
diff --git a/content/common/common.gni b/content/common/common.gni
index e192ae281c26b101357b54bd6f794e11e278c52d..2622b770c6b5c8e96d90e19aacf2aabbf0de1414 100644
--- a/content/common/common.gni
+++ b/content/common/common.gni
@@ -13,8 +13,9 @@ content_common_gypi_values =
                 [ "../content_common.gypi" ])
 
 declare_args() {
-  # TODO(henryhsu): This flag should be removed after the linux header of
-  # trybot is updated.
+  # Indicates if V4L plugin is used.
+  use_v4lplugin = false
+
   # Indicates if Video4Linux2 codec is used. This is used for x86 CrOS

[wuchengli, 2015/01/21 12:50:42]

Update the comment. This will be used by both x86 and arm. Right?

[henryhsu, 2015/01/21 13:00:40]

No. The condition is (arm || (use_ozone && use_v4l2_codec)). So use_v4l2_codec
is only for x86 CrOS.

[Pawel Osciak, 2015/01/22 08:30:02]

Yes, but the name would be misleading then, and that's not the intention. I'd
rather we had use_v4l2_codec on all platforms, since it's used to save us from
non-CrOS builds, and should be enabled on all CrOS.

[henryhsu, 2015/01/22 09:09:09]

Done.

[Pawel Osciak, 2015/01/23 05:50:47]

If done, then I think we should not have to check for ARM for V4L2(S)VDA, but
for use_v4l2_codec instead?

   # platform which has v4l2 hardware encoder / decoder.
   use_v4l2_codec = false