Mojo: Make GetDefault{AsyncWaiter,Logger} static methods of Environment.

mojo/public/cpp/gles2/gles2.h

Index: mojo/public/cpp/gles2/gles2.h
diff --git a/mojo/public/cpp/gles2/gles2.h b/mojo/public/cpp/gles2/gles2.h
index 4c1156e910f561c968da06af93d6284c6783048b..a408fc701ebeb3b1a606e2505a366a33f21c06c7 100644
--- a/mojo/public/cpp/gles2/gles2.h
+++ b/mojo/public/cpp/gles2/gles2.h
@@ -6,14 +6,14 @@
 #define MOJO_PUBLIC_CPP_GLES2_GLES2_H_
 
 #include "mojo/public/c/gles2/gles2.h"
-#include "mojo/public/cpp/environment/default_async_waiter.h"
+#include "mojo/public/cpp/environment/environment.h"
 
 namespace mojo {
 
 class GLES2Initializer {
  public:
-  explicit GLES2Initializer(
-      const MojoAsyncWaiter* async_waiter = GetDefaultAsyncWaiter()) {
+  explicit GLES2Initializer(const MojoAsyncWaiter* async_waiter =
+                                Environment::GetDefaultAsyncWaiter()) {
     MojoGLES2Initialize(async_waiter);
   }
   ~GLES2Initializer() { MojoGLES2Terminate(); }