Delete some unused code found by -Wunused-function

content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h"
 
 #include "third_party/khronos/GLES2/gl2.h"
 #ifndef GL_GLEXT_PROTOTYPES
 #define GL_GLEXT_PROTOTYPES 1
 #endif
@@ skipping 26 matching lines @@
 #include "gpu/ipc/command_buffer_proxy.h"
 #include "webkit/glue/gl_bindings_skia_cmd_buffer.h"
 
 static base::LazyInstance<base::Lock>::Leaky
     g_all_shared_contexts_lock = LAZY_INSTANCE_INITIALIZER;
 static base::LazyInstance<std::set<WebGraphicsContext3DCommandBufferImpl*> >
     g_all_shared_contexts = LAZY_INSTANCE_INITIALIZER;
 
 namespace {
 
-void ClearSharedContexts() {
-  base::AutoLock lock(g_all_shared_contexts_lock.Get());
-  g_all_shared_contexts.Pointer()->clear();
-}
-
 void ClearSharedContextsIfInShareSet(
     WebGraphicsContext3DCommandBufferImpl* context) {
   // If the given context isn't in the share set, that means that it
   // or another context it was previously sharing with already
   // provoked a lost context. Other contexts might have since been
   // successfully created and added to the share set, so do not clear
   // out the share set unless we know that all the contexts in there
   // are supposed to be lost simultaneously.
   base::AutoLock lock(g_all_shared_contexts_lock.Get());
   std::set<WebGraphicsContext3DCommandBufferImpl*>* share_set =
@@ skipping 1531 matching lines @@
     swap_client_->OnViewContextSwapBuffersAborted();
 }
 
 void WebGraphicsContext3DCommandBufferImpl::OnErrorMessage(
     const std::string& message, int id) {
   if (error_message_callback_) {
     WebKit::WebString str = WebKit::WebString::fromUTF8(message.c_str());
     error_message_callback_->onErrorMessage(str, id);
   }
 }