Add sampler related ES3 APIs to command buffer.

gpu/command_buffer/service/context_group.h

Index: gpu/command_buffer/service/context_group.h
diff --git a/gpu/command_buffer/service/context_group.h b/gpu/command_buffer/service/context_group.h
index b6b64830803d1ea2808a9f599bf9e4888ce07a53..7477674af60c5a585ab51e09784659ac7a7957f1 100644
--- a/gpu/command_buffer/service/context_group.h
+++ b/gpu/command_buffer/service/context_group.h
@@ -5,6 +5,7 @@
 #ifndef GPU_COMMAND_BUFFER_SERVICE_CONTEXT_GROUP_H_
 #define GPU_COMMAND_BUFFER_SERVICE_CONTEXT_GROUP_H_
 
+#include <map>
 #include <string>
 #include <vector>
 #include "base/basictypes.h"
@@ -174,6 +175,24 @@ class GPU_EXPORT ContextGroup : public base::RefCounted<ContextGroup> {
     draw_buffer_ = buf;
   }
 
+  void AddSamplerId(GLuint client_id, GLuint service_id) {
+    samplers_id_map_[client_id] = service_id;
+  }
+
+  bool GetSamplerServiceId(GLuint client_id, GLuint* service_id) const {
+    std::map<GLuint, GLuint>::const_iterator iter =
+        samplers_id_map_.find(client_id);
+    if (iter == samplers_id_map_.end())
+      return false;
+    if (service_id)
+      *service_id = iter->second;
+    return true;
+  }
+
+  void RemoveSamplerId(GLuint client_id) {
+    samplers_id_map_.erase(client_id);
+  }
+
  private:
   friend class base::RefCounted<ContextGroup>;
   ~ContextGroup();
@@ -223,6 +242,9 @@ class GPU_EXPORT ContextGroup : public base::RefCounted<ContextGroup> {
 
   std::vector<base::WeakPtr<gles2::GLES2Decoder> > decoders_;
 
+  // Mappings from client side IDs to service side IDs.
+  std::map<GLuint, GLuint> samplers_id_map_;
+
   GLenum draw_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(ContextGroup);