Reason for revert: This CL breaks internal dependencies. Original issue's description: > New statistics interface for APM > > This adds functions to enable and retrieve statistics from APM. These functions are not yet called, which will happen in a follow-up CL. > > BUG=webrtc:6525 > > Committed: https://crrev.com/8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4 > Cr-Commit-Position: refs/heads/master@{#14810} TBR=peah@webrtc.org,solenberg@webrtc.org # Skipping CQ checks because original CL landed less than 1 days ago. NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true BUG=webrtc:6525 Review-Url: https://codereview.webrtc.org/2456333002 Cr-Commit-Position: refs/heads/master@{#14814}