Mojo C++ bindings: more consistent Clone() and Equals().

mojo/public/cpp/system/handle.h

Index: mojo/public/cpp/system/handle.h
diff --git a/mojo/public/cpp/system/handle.h b/mojo/public/cpp/system/handle.h
index f83a9226f1891e2904341f54d01c75d32bfb8678..d0466b0ddead9ae80b1b8e95964df058fda19b37 100644
--- a/mojo/public/cpp/system/handle.h
+++ b/mojo/public/cpp/system/handle.h
@@ -122,6 +122,10 @@ class ScopedHandleBase {
 
   bool is_valid() const { return handle_.is_valid(); }
 
+  bool operator==(const ScopedHandleBase& other) const {
+    return handle_.value() == other.get().value();
+  }
+
  private:
   void CloseIfNecessary() {
     if (handle_.is_valid())