Revert "tcmalloc: Move existing tcmalloc files under gperftools-2.0."

This reverts commit 615e0342e44cbe073b1958ab9f5a318d799f6f34.

Reason for revert: breaks compilation with enable_profiling = true

Original change's description:
> tcmalloc: Move existing tcmalloc files under gperftools-2.0.
> 
> Move existing tcmalloc files, both vendor and chromium, under gperftools-2.0
> in preparation for upreving tcmalloc to the most recent gperftools version.
> 
> This CL did:
> 
>   # Create a gerftools-2.0 folder.
>   mkdir gperftools-2.0
> 
>   # Move vendor/ and chromium/ under the new folder.
>   git mv vendor gperftools-2.0/vendor
>   git mv chromium gperftools-2.0/chromium
> 
>   # Update //base/allocator/BUILD.gn to have tcmalloc_dir point to
>   # //third_party/tcmalloc/gperftools-2.0/chromium/src.
>   # Update addr2line-pdb sources in tcmalloc/BUILD.gn.
>   # Update include paths in files under //base/process and //base/allocator.
> 
> This is old code that uses currently banned functions.
> NOPRESUBMIT=true
> 
> BUG=724399,b:70905156
> 
> Change-Id: I498a6edda48e178bbacfb41e30f75e9e96e336fc
> Reviewed-on: https://chromium-review.googlesource.com/1130670
> Reviewed-by: Will Harris <wfh@chromium.org>
> Commit-Queue: Gabriel Marin <gmx@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#574346}

TBR=wfh@chromium.org,gmx@chromium.org

Change-Id: Ifdd162a045009444621c6e3052f348919fdafc96
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 724399, b:70905156
Reviewed-on: https://chromium-review.googlesource.com/1135266
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574561}
530 files changed