Merge Conflict Fix CL to lmp-mr1-release for ag/849478

DO NOT MERGE - libvpx: Pull from upstream

Current HEAD: 7105df53d7dc13d5e575bc8df714ec8d1da36b06

BUG=23452792

Change-Id: Ic78176fc369e0bacc71d423e0e2e6075d004aaec

   virtual void BeginPassHook(unsigned int /*pass*/) {
     psnr_ = kMaxPsnr;
     nframes_ = 0;
 }

   virtual void BeginPassHook(unsigned int /*pass*/) {
     psnr_ = kMaxPsnr;
     nframes_ = 0;
 }
