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

content/browser/loader/resource_dispatcher_host_unittest.cc

Index: content/browser/loader/resource_dispatcher_host_unittest.cc
diff --git a/content/browser/loader/resource_dispatcher_host_unittest.cc b/content/browser/loader/resource_dispatcher_host_unittest.cc
index 2358200d7dacf8a015fe5e00381a06e2f69b7da4..8e619ddfa902e81e2ba5303f30f5922779a5a010 100644
--- a/content/browser/loader/resource_dispatcher_host_unittest.cc
+++ b/content/browser/loader/resource_dispatcher_host_unittest.cc
@@ -180,8 +180,8 @@ class MockURLRequestContextSelector
 // messages to go to the same place, which is why this forwards.
 class ForwardingFilter : public ResourceMessageFilter {
  public:
-  explicit ForwardingFilter(IPC::Sender* dest,
-                            ResourceContext* resource_context)
+  ForwardingFilter(IPC::Sender* dest,
+                   ResourceContext* resource_context)
     : ResourceMessageFilter(
         ChildProcessHostImpl::GenerateChildProcessUniqueId(),
         PROCESS_TYPE_RENDERER,