mac: Prepare for -Wunused-functions.

content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc

Index: content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
index e6d4df5da387e41fe7f2bc8014db064754d33fe9..6f06b348e3f0e2e1a3aa907793a3a6025f0ace07 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -50,12 +50,6 @@ typedef std::multimap<GpuChannelHost*, WebGraphicsContext3DCommandBufferImpl*>
 static base::LazyInstance<ContextMap> g_all_shared_contexts =
     LAZY_INSTANCE_INITIALIZER;
 
-size_t ClampUint64ToSizeT(uint64 value) {
-  value = std::min(value,
-                   static_cast<uint64>(std::numeric_limits<size_t>::max()));
-  return static_cast<size_t>(value);
-}
-
 uint32_t GenFlushID() {
   static base::subtle::Atomic32 flush_id = 0;