Revert of gpu: support GL_TEXTURE_CUBE_MAP destination target to Copy(Sub)TextureCHROMIUM.

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index 098a9eed5965e7255926ac1647bdd165670fea19..e30e2e38c74705a99d7b14f1f8acabaa8a0aac26 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -809,27 +809,6 @@ size_t GLES2Util::GLTargetToFaceIndex(uint32 target) {
   }
 }
 
-uint32_t GLES2Util::GLTextureTargetToBindingTarget(uint32_t textarget) {
-  switch (textarget) {
-    case GL_TEXTURE_2D:
-    case GL_TEXTURE_EXTERNAL_OES:
-    case GL_TEXTURE_RECTANGLE_ARB:
-    case GL_TEXTURE_3D:
-    case GL_TEXTURE_2D_ARRAY:
-      return textarget;
-    case GL_TEXTURE_CUBE_MAP_POSITIVE_X:
-    case GL_TEXTURE_CUBE_MAP_NEGATIVE_X:
-    case GL_TEXTURE_CUBE_MAP_POSITIVE_Y:
-    case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y:
-    case GL_TEXTURE_CUBE_MAP_POSITIVE_Z:
-    case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z:
-      return GL_TEXTURE_CUBE_MAP;
-    default:
-      NOTREACHED();
-      return GL_TEXTURE_2D;
-  }
-}
-
 uint32 GLES2Util::GetGLReadPixelsImplementationFormat(
     uint32 internal_format) {
   switch (internal_format) {