Revert of cc: Add mailbox support to ResourceProvider write locks.

cc/trees/layer_tree_host_unittest_context.cc

Index: cc/trees/layer_tree_host_unittest_context.cc
diff --git a/cc/trees/layer_tree_host_unittest_context.cc b/cc/trees/layer_tree_host_unittest_context.cc
index fd9e73f8818505d4e6a3b98f41ed8020753f0a4b..2f4c2424bae26a504a0b5a558688803330792e98 100644
--- a/cc/trees/layer_tree_host_unittest_context.cc
+++ b/cc/trees/layer_tree_host_unittest_context.cc
@@ -942,7 +942,7 @@
     ResourceId resource = child_resource_provider_->CreateResource(
         gfx::Size(4, 4), ResourceProvider::TEXTURE_HINT_IMMUTABLE, RGBA_8888);
     ResourceProvider::ScopedWriteLockGL lock(child_resource_provider_.get(),
-                                             resource, false);
+                                             resource);
 
     gpu::Mailbox mailbox;
     gl->GenMailboxCHROMIUM(mailbox.name);