Mojo C++ bindings: switch device/vr mojom target to use STL/WTF types.

third_party/WebKit/Source/modules/vr/VRPose.cpp

Index: third_party/WebKit/Source/modules/vr/VRPose.cpp
diff --git a/third_party/WebKit/Source/modules/vr/VRPose.cpp b/third_party/WebKit/Source/modules/vr/VRPose.cpp
index 3775522ddad665fc97f4a7fc1d52d8b3e7cfca48..8007fc5cc4c9778d1406c5e3dd0787df620b5870 100644
--- a/third_party/WebKit/Source/modules/vr/VRPose.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRPose.cpp
@@ -8,11 +8,12 @@ namespace blink {
 
 namespace {
 
-DOMFloat32Array* mojoArrayToFloat32Array(const mojo::WTFArray<float>& vec) {
-  if (vec.is_null())
+DOMFloat32Array* mojoArrayToFloat32Array(
+    const WTF::Optional<WTF::Vector<float>>& vec) {
+  if (!vec)
     return nullptr;
 
-  return DOMFloat32Array::create(&(vec.front()), vec.size());
+  return DOMFloat32Array::create(&(vec.value().first()), vec.value().size());
 }
 
 }  // namespace