Use aom_usec_timer for timing
Use aom_usec_timer for timing

Change-Id: I71faf1d2046b00ce87f85061336d840e5ffe3743

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom