ui: Move software fallback decisions to GpuProcessTransportFactory.

ui/compositor/test/in_process_context_factory.cc

Index: ui/compositor/test/in_process_context_factory.cc
diff --git a/ui/compositor/test/in_process_context_factory.cc b/ui/compositor/test/in_process_context_factory.cc
index 54a066a235fb00883d051429ab5f7e27ea457e44..6568831c4df2dba95e971e825f027258039c927b 100644
--- a/ui/compositor/test/in_process_context_factory.cc
+++ b/ui/compositor/test/in_process_context_factory.cc
@@ -81,9 +81,7 @@ InProcessContextFactory::~InProcessContextFactory() {
 }
 
 void InProcessContextFactory::CreateOutputSurface(
-    base::WeakPtr<Compositor> compositor,
-    bool software_fallback) {
-  DCHECK(!software_fallback);
+    base::WeakPtr<Compositor> compositor) {
   gpu::gles2::ContextCreationAttribHelper attribs;
   attribs.alpha_size = 8;
   attribs.blue_size = 8;