Revert 84486 - Merge gpu_trace_event back into base/debug/trace_event.Initial land attempt at htt...

Revert 84486 - Merge gpu_trace_event back into base/debug/trace_event.Initial land attempt at http://codereview.chromium.org/6551019/gpu_trace_event fork at http://codereview.chromium.org/6691013- gpu_trace_event renamed to base/debug/trace_event and modified as appropriate for base::debug- Unit Tests implemented for trace_event- gpu_common library removed (was added only for gpu_trace_event)- Existing calls to trace_event suffixed with _ETW to make ETW calls (see decisions and incremental plans at end of 6551019)- GPU trace calls renamed to new calls.- Tracing switch removed from test_shell, as linux log file support removed.BUG=79509
TEST=trace_event_win_unittest and about:gpuCommitted: http://src.chromium.org/viewvc/chrome?view=rev&revision=84284Review URL: http://codereview.chromium.org/6862002
TBR=scheib@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=84494