Mojo: Add GetMinimumLogLevel() to the logger interface.

mojo/public/cpp/environment/environment.h

Index: mojo/public/cpp/environment/environment.h
diff --git a/mojo/public/cpp/environment/environment.h b/mojo/public/cpp/environment/environment.h
index f75e2f77851d8da0a40a52f6e3c305c57e2b7fd9..3cc179a8959f4737f42fed7fd3f99592dc5f35a8 100644
--- a/mojo/public/cpp/environment/environment.h
+++ b/mojo/public/cpp/environment/environment.h
@@ -5,16 +5,20 @@
 #ifndef MOJO_PUBLIC_CPP_ENVIRONMENT_ENVIRONMENT_H_
 #define MOJO_PUBLIC_CPP_ENVIRONMENT_ENVIRONMENT_H_
 
+#include "mojo/public/c/environment/logger.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
 
-// This class must be instantiated before using any Mojo APIs.
+// This class must be instantiated before using any Mojo C++ APIs.
 class Environment {
  public:
   Environment();
   ~Environment();
 
+  // Note: Not thread-safe; the default logger must not be used concurrently.
+  static void SetMinimumLogLevel(MojoLogLevel minimum_log_level);
+
  private:
   MOJO_DISALLOW_COPY_AND_ASSIGN(Environment);
 };