mac: Prepare for -Wunused-functions.

gpu/command_buffer/client/gl_in_process_context.cc

Index: gpu/command_buffer/client/gl_in_process_context.cc
diff --git a/gpu/command_buffer/client/gl_in_process_context.cc b/gpu/command_buffer/client/gl_in_process_context.cc
index 566b0832512708876a171ccae96cf32681d81367..a1ca1a2727e60745f7d504c4711b5ccdf89a094a 100644
--- a/gpu/command_buffer/client/gl_in_process_context.cc
+++ b/gpu/command_buffer/client/gl_in_process_context.cc
@@ -91,11 +91,6 @@ base::LazyInstance<base::Lock> g_all_shared_contexts_lock =
 base::LazyInstance<std::set<GLInProcessContextImpl*> > g_all_shared_contexts =
     LAZY_INSTANCE_INITIALIZER;
 
-size_t SharedContextCount() {
-  base::AutoLock lock(g_all_shared_contexts_lock.Get());
-  return g_all_shared_contexts.Get().size();
-}
-
 GLInProcessContextImpl::GLInProcessContextImpl()
     : share_group_id_(0), context_lost_(false) {}