[Mojo Video Capture] Add test coverage for accelerated jpeg decoding

media/gpu/BUILD.gn

Index: media/gpu/BUILD.gn
diff --git a/media/gpu/BUILD.gn b/media/gpu/BUILD.gn
index e026eee6778a441fb5638e30d189ad5c946ba9c6..3b14919bc1ad6eb4fb8356b0ee2d0197a747e2d2 100644
--- a/media/gpu/BUILD.gn
+++ b/media/gpu/BUILD.gn
@@ -128,6 +128,8 @@ component("gpu") {
   defines = [ "MEDIA_GPU_IMPLEMENTATION" ]
 
   sources = [
+    "fake_jpeg_decode_accelerator.cc",
+    "fake_jpeg_decode_accelerator.h",

[sandersd (OOO until July 31), 2017/03/14 23:02:34]

Are we sure we want to always build this? It seems dangerous to have this code
accessible in the GPU process if it's not necessary.

[chfremer, 2017/03/15 17:31:05]

I assumed that this would be okay, considering that we also always build
fake_video_decode_accelerator.cc. What is the concrete danger you are seeing?

[sandersd (OOO until July 31), 2017/03/15 17:38:12]

While I don't think either should be in a release buid, FakeVideoDecoder does
nothing but FakeJpegDecoder actually decodes JPEGs.

I do not know the JPEG stack well enough to know if this is an attack surface
increase vs. the regular accelerated path.

     "fake_video_decode_accelerator.cc",
     "fake_video_decode_accelerator.h",
     "gpu_video_accelerator_util.cc",
@@ -146,6 +148,7 @@ component("gpu") {
     "//ui/gfx/geometry",
   ]
   deps = [
+    "//third_party/libyuv:libyuv",
     "//ui/base",
     "//ui/display/types",
     "//ui/gl",