Add GL State Restoring Functions

gpu/command_buffer/service/texture_manager.cc

Index: gpu/command_buffer/service/texture_manager.cc
diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index a9238aaa47fb3e65eea4a782853e7c96901f4e34..3937e4819a12a7e7731009d393898472a4d95da6 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -1106,8 +1106,8 @@ TextureManager::TextureInfo* TextureManager::CreateTextureInfo(
 }
 
 TextureManager::TextureInfo* TextureManager::GetTextureInfo(
-    GLuint client_id) {
-  TextureInfoMap::iterator it = texture_infos_.find(client_id);
+    GLuint client_id) const {
+  TextureInfoMap::const_iterator it = texture_infos_.find(client_id);
   return it != texture_infos_.end() ? it->second : NULL;
 }