Refactor context creation parameters into a struct.

ui/gl/gl_context_stub.cc

Index: ui/gl/gl_context_stub.cc
diff --git a/ui/gl/gl_context_stub.cc b/ui/gl/gl_context_stub.cc
index 9b42a093971c27993123b525ec7116b6fcdc60b6..a72f08080cc06d5b3f7c341c6bd1e9480a046316 100644
--- a/ui/gl/gl_context_stub.cc
+++ b/ui/gl/gl_context_stub.cc
@@ -12,8 +12,8 @@ GLContextStub::GLContextStub() : GLContextReal(nullptr) {}
 GLContextStub::GLContextStub(GLShareGroup* share_group)
     : GLContextReal(share_group) {}
 
-bool GLContextStub::Initialize(
-    GLSurface* compatible_surface, GpuPreference gpu_preference) {
+bool GLContextStub::Initialize(GLSurface* compatible_surface,
+                               const GLContextAttribs& attribs) {
   return true;
 }