Finish NV12 support via streams.

The main functionality for NV12 texture support through EGL streams has
been added. Updates to the compiler, texture code, and stream code were
added to support binding to external D3D11 NV12 textures. An end2end test
was also added to test sampling of YUV textures and converting to RGB.
There is also a new script to convert BMP files to an NV12 texture ready
to load into D3D11 for testing purposes.

BUG=angleproject:1332

Change-Id: I39b6ec393ea338e2c843fb911acc1b36cd1158a0
Reviewed-on: https://chromium-review.googlesource.com/339454
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Ian Ewell <ewell@google.com>
Reviewed-on: https://chromium-review.googlesource.com/341254
Reviewed-by: Ian Ewell <ewell@google.com>
diff --git a/src/libANGLE/Compiler.cpp b/src/libANGLE/Compiler.cpp
index fc48d8e..7bf5073 100644
--- a/src/libANGLE/Compiler.cpp
+++ b/src/libANGLE/Compiler.cpp
@@ -52,6 +52,7 @@
     mResources.EXT_shader_texture_lod       = extensions.shaderTextureLOD;
     // TODO: disabled until the extension is actually supported.
     mResources.OES_EGL_image_external = 0;
+    mResources.NV_EGL_stream_consumer_external = extensions.eglStreamConsumerExternal;
     // TODO: use shader precision caps to determine if high precision is supported?
     mResources.FragmentPrecisionHigh = 1;
     mResources.EXT_frag_depth        = extensions.fragDepth;