Add missing (and remove superfluous) 'explicit' from constructors.

content/public/browser/child_process_data.h

Index: content/public/browser/child_process_data.h
diff --git a/content/public/browser/child_process_data.h b/content/public/browser/child_process_data.h
index 4b5a61c09a0f68fd983452352d0d4c2673b75fe8..bc3a973d434572a33d99214479a5f8f994376fba 100644
--- a/content/public/browser/child_process_data.h
+++ b/content/public/browser/child_process_data.h
@@ -29,9 +29,9 @@ struct ChildProcessData {
   // The handle to the process.
   base::ProcessHandle handle;
 
-  ChildProcessData(content::ProcessType type)
+  explicit ChildProcessData(content::ProcessType type)
       : type(type), id(0), handle(base::kNullProcessHandle) {
-  }
+}
 };
 
 }  // namespace content