Revert "Track progress through View destructor"

This reverts commit 24e521c6.

Reason for revert: bug has been found and fixed

Original change's description:
> Track progress through View destructor
>
> The View destructor ends up in an impossible state which means that
> execution must have branched to the middle of it, but it is not clear
> how this could happen. This change adds an array of line numbers that is
> filled in as the destructor runs to leave us some bread crumbs. It also
> records the vtable of the about-to-be-deleted child object so that we
> can investigate if this is a type-related bug.
>
> Bug: 1152152
> Change-Id: I386507974a8b6ccd1914e0ec62151456411f0c19
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2572793
> Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
> Reviewed-by: Robert Liao <robliao@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#833875}

TBR=robliao@chromium.org,brucedawson@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1152152
Change-Id: I62871ab84d1a219c9eed67bc2ce3d0b4ceed44c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2580545Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Commit-Queue: Robert Liao <robliao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834999}

ui/views/view.cc

@@ -11,7 +11,6 @@
 #include "base/check_op.h"
 #include "base/command_line.h"
 #include "base/containers/adapters.h"
-#include "base/debug/alias.h"
 #include "base/feature_list.h"
 #include "base/i18n/rtl.h"
 #include "base/macros.h"
@@ -192,19 +191,8 @@ View::View() {
 }
 
 View::~View() {
-  // Line number history to see the path through this function prior to a
-  // mysterious crash (https://crbug.com/1152152).
-  constexpr size_t kNumEntries = 16;
-  int line_number_trace[kNumEntries] = {};
-  base::debug::Alias(&line_number_trace[0]);
-  size_t next_line_entry = 0;
-  base::debug::Alias(&next_line_entry);
-  void* vtable = nullptr;
-  base::debug::Alias(&vtable);
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
   if (parent_)
     parent_->RemoveChildView(this);
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 
   // This view should have been removed from the focus list by now.
   DCHECK_EQ(next_focusable_view_, nullptr);
@@ -216,48 +204,34 @@ View::~View() {
   // layout managers access child view properties, this would result in a
   // use-after-free error.
   layout_manager_.reset();
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 
   {
     internal::ScopedChildrenLock lock(this);
     for (auto* child : children_) {
-      line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
       child->parent_ = nullptr;
-      line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 
       // Since all children are removed here, it is safe to set
       // |child|'s focus list pointers to null and expect any references
       // to |child| will be removed subsequently.
       child->next_focusable_view_ = nullptr;
       child->previous_focusable_view_ = nullptr;
-      line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 
-      if (!child->owned_by_client_) {
-        // Extract the vtable pointer to allow post-mortem identification of the
-        // object type.
-        if (child)
-          vtable = reinterpret_cast<void**>(child)[0];
+      if (!child->owned_by_client_)
         delete child;
     }
-      line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
-    }
   }
 
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
   for (ViewObserver& observer : observers_)
     observer.OnViewIsDeleting(this);
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 
   for (ui::Layer* layer_beneath : layers_beneath_)
     layer_beneath->RemoveObserver(this);
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 
   // Clearing properties explicitly here lets us guarantee that properties
   // outlive |this| (at least the View part of |this|). This is intentionally
   // called at the end so observers can examine properties inside
   // OnViewIsDeleting(), for instance.
   ClearProperties();
-  line_number_trace[(next_line_entry++) % kNumEntries] = __LINE__;
 }
 
 // Tree operations -------------------------------------------------------------