Fixed some warnings.

command_buffer/service/cross/gl/geometry_gl.cc

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 224 matching lines @@
 inline unsigned int GetAttribIndex(vertex_struct::Semantic semantic,
                                    unsigned int semantic_index) {
   switch (semantic) {
     case vertex_struct::POSITION:
       DCHECK_EQ(semantic_index, 0);
       return 0;
     case vertex_struct::NORMAL:
       DCHECK_EQ(semantic_index, 0);
       return 2;
     case vertex_struct::COLOR:
-      DCHECK_LT(semantic_index, 2);
+      DCHECK_LT(semantic_index, 2U);
       return 3 + semantic_index;
     case vertex_struct::TEX_COORD:
-      DCHECK_LT(semantic_index, 8);
+      DCHECK_LT(semantic_index, 8U);
       return 8 + semantic_index;
     default:
       DLOG(FATAL) << "Not reached.";
       return 0;
   }
 }
 
 inline void ExtractSizeTypeNormalized(vertex_struct::Type type,
                                       GLint *size,
                                       GLenum *gl_type,
@@ skipping 285 matching lines @@
     return BufferSyncInterface::kParseInvalidArguments;
   }
   glDrawRangeElements(gl_mode, min_index, max_index, count, index_type,
                       OffsetToPtr(offset));
   CHECK_GL_ERROR();
   return BufferSyncInterface::kParseNoError;
 }
 
 }  // namespace command_buffer
 }  // namespace o3d