Fix incompatibility between two experiments
Fix incompatibility between two experiments

ext_tile is not compatible with reference_buffer, this commit changes
to disable refrence_buffer when ext_tile is enabled.

BUG=aomedia:114

Change-Id: I6416f4c731bec1c4cfeab3cdb539f359627ed2e2

smarter/aom,luctrudeau/aom,GrokImageCompression/aom,smarter/aom,smarter/aom,GrokImageCompression/aom,luctrudeau/aom,GrokImageCompression/aom,smarter/aom,luctrudeau/aom,smarter/aom,luctrudeau/aom,smarter/aom,luctrudeau/aom,GrokImageCompression/aom,luctrudeau/aom,GrokImageCompression/aom,GrokImageCompression/aom