Revert "Roll src/third_party/libunwindstack/ dfd3f3d84..de5bb5ebd (1 commit)"

This reverts commit a6207513.

Reason for revert: causing build failures on https://ci.chromium.org/p/chromium/builders/try/android_compile_x64_dbg/1504

Original change's description:
> Roll src/third_party/libunwindstack/ dfd3f3d84..de5bb5ebd (1 commit)
> 
> https://chromium.googlesource.com/chromium/src/third_party/libunwindstack.git/+log/dfd3f3d84cfc..de5bb5ebd6d7
> 
> $ git log dfd3f3d84..de5bb5ebd --date=short --no-merges --format='%ad %ae %s'
> 2020-05-19 wittman [Sampling profiler] Include AsmGetRegs asm functions on x86/x64
> 
> Created with:
>   roll-dep src/third_party/libunwindstack
> 
> Bug: 1004855
> 
> R=​etiennep@chromium.org
> 
> Change-Id: If6c111aae6dbfb4bf474b57dba6274e63fb8cbb4
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2210496
> Commit-Queue: Mike Wittman <wittman@chromium.org>
> Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
> Auto-Submit: Mike Wittman <wittman@chromium.org>
> Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#770701}

TBR=wittman@chromium.org,etiennep@chromium.org

Change-Id: I73b4a976214f47e3347cee7483ce7aebe7ec4662
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1004855
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212443Reviewed-by: Mike Wittman <wittman@chromium.org>
Commit-Queue: Mike Wittman <wittman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771047}

DEPS

@@ -1115,7 +1115,7 @@ deps = {
   },
 
   'src/third_party/libunwindstack': {
-      'url': Var('chromium_git') + '/chromium/src/third_party/libunwindstack.git' + '@' + 'de5bb5ebd6d792a622646abde269608fd7e44179',
+      'url': Var('chromium_git') + '/chromium/src/third_party/libunwindstack.git' + '@' + 'dfd3f3d84cfc222af93bc86b276414fc690977da',
       'condition': 'checkout_android',
   },