Add YUV_420_BIPLANAR to gfx::BufferFormat.

content/common/gpu/client/gpu_memory_buffer_impl.cc

Index: content/common/gpu/client/gpu_memory_buffer_impl.cc
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl.cc b/content/common/gpu/client/gpu_memory_buffer_impl.cc
index cc0ac0044ac2997e2a9d6782d171e202a8ea4ad0..a294323f666a6707a7db9ec268aaa7fc18bcbd0a 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl.cc
+++ b/content/common/gpu/client/gpu_memory_buffer_impl.cc
@@ -97,6 +97,11 @@ size_t GpuMemoryBufferImpl::SubsamplingFactor(gfx::BufferFormat format,
       DCHECK_LT(static_cast<size_t>(plane), arraysize(factor));
       return factor[plane];
     }
+    case gfx::BufferFormat::YUV_420_BIPLANAR: {
+      static size_t factor[] = {1, 2};
+      DCHECK_LT(static_cast<size_t>(plane), arraysize(factor));
+      return factor[plane];
+    }
   }
   NOTREACHED();
   return 0;
@@ -144,6 +149,10 @@ bool GpuMemoryBufferImpl::RowSizeInBytes(size_t width,
       DCHECK_EQ(width % 2, 0u);
       *size_in_bytes = width / SubsamplingFactor(format, plane);
       return true;
+    case gfx::BufferFormat::YUV_420_BIPLANAR:
+      DCHECK_EQ(width % 2, 0u);
+      *size_in_bytes = width;

[reveman, 2015/08/10 20:28:16]

hm, is this really what we want here? seems like BufferSizeInBytes is not going
to return the correct value when this returns |width| for plane 1 and 2.

[Andre, 2015/08/10 21:09:48]

Hmm, I'm not seeing why it's wrong.
Let's say size is 10x10, so U and V are both 5x5.
For the Y plane: rowsize=10, subsampling=1, buffersize=100.
For the interleaved UV plane: rowsize=10, subsampling=2, buffersize=50 (rowsize
* height / subsampling = 10 * 10 / 2).

Am I understanding this correctly?

[reveman, 2015/08/10 22:40:54]

Yes, that looks correct. Sorry my bad. Still thinking in terms of 3 planes for
some reason..

+      return true;
   }
   NOTREACHED();
   return false;