Remove dead code paths around PIXEL_STORAGE_TEXTURE in capture pipeline.

media/base/video_frame.cc

Index: media/base/video_frame.cc
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc
index f14e91fa6d3f38c7e5b905eb66aba072db029eaa..97bbb49364d86238810298294e78a7e877ea60fb 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -830,6 +830,8 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalStorage(
     size_t data_offset) {
   DCHECK(IsStorageTypeMappable(storage_type));
 
+  // TODO(miu): This function should support any pixel format.
+  // http://crbug.com/555909
   if (format != PIXEL_FORMAT_I420) {
     DLOG(ERROR) << "Only PIXEL_FORMAT_I420 format supported: "
                 << VideoPixelFormatToString(format);
@@ -853,6 +855,10 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalStorage(
                            natural_size, timestamp);
   }
   frame->strides_[kYPlane] = coded_size.width();
+  // TODO(miu): This always rounds widths down, whereas VideoFrame::RowBytes()
+  // always rounds up.  This inconsistency must be resolved.  Perhaps a
+  // CommonAlignment() check should be made in IsValidConfig()?
+  // http://crbug.com/555909
   frame->strides_[kUPlane] = coded_size.width() / 2;
   frame->strides_[kVPlane] = coded_size.width() / 2;
   frame->data_[kYPlane] = data;