Fix missing symbols for pre-linking of the Cast sender library for iOS.

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 c837159958739edb5d4d3708d1dab8af0bc45562..ceb3858f2fbe7a1e41a7a6c1833d432176a13027 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -478,6 +478,7 @@ scoped_refptr<VideoFrame> VideoFrame::CreateEOSFrame() {
                         true);
 }
 
+#if !defined(MEDIA_FOR_CAST_IOS)
 // static
 scoped_refptr<VideoFrame> VideoFrame::CreateColorFrame(

[miu, 2015/03/27 21:26:26]

I don't understand: Why can't these be compiled in for IOS always?  I don't see
any special "depends on libyuv" or "calls into custom asm code" here.  FillYUV()
just memset's everything.

If I'm wrong about this, consider leaving the functions defined, and just wrap
the calls to FillYUV() with the #if !defined(...), and please be sure to comment
why.

[jfroy, 2015/03/27 21:33:25]

FillYUV is defined in yuv_convert.cc, which will select CPU-optimized
implementations. The problem is that it selects SSE functions when compiling for
the iOS simulator, but the simd code is not properly compiled when configuring
the build with target_subarch=both target_arch=arm. If you try to enable the
simd code for the simulator, you end up with a broken iOS hardware build.

It is really better to leave the functions defined when they won't in fact work
correctly? Seems worse than defining them out.

Ultimately, and from what I can tell from the bug tracker, those build issues
will be fixed in GN.

     const gfx::Size& size,
@@ -509,6 +510,7 @@ scoped_refptr<VideoFrame> VideoFrame::CreateTransparentFrame(
   FillYUVA(frame.get(), kBlackY, kBlackUV, kBlackUV, kTransparentA);
   return frame;
 }
+#endif  // defined(MEDIA_FOR_CAST_IOS)
 
 #if defined(VIDEO_HOLE)
 // This block and other blocks wrapped around #if defined(VIDEO_HOLE) is not