Revert "Add support for lldbinit to macOS."

This reverts commit 4fa0fac0.

Reason for revert: Tests hit the DCHECK on Mac Retina Debug (AMD) tester: https://crbug.com/999065

Original change's description:
> Add support for lldbinit to macOS.
> 
> The build-flag `strip_absolute_paths_from_debug_symbols = 1` produces
> deterministic outputs and has better goma caching, but breaks lldb. This CL adds
> machinery to help users get functional symbols in lldb while still using that
> compile flag.
> 
> Bug: 330262
> Change-Id: I42f1e6c9c76296d451730ea481d7e1c3c0a69476
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1775227
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Commit-Queue: Erik Chen <erikchen@chromium.org>
> Auto-Submit: Erik Chen <erikchen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#691393}

TBR=thakis@chromium.org,erikchen@chromium.org

Change-Id: I801cd3afe2b1b89b050c7806d62295a4a269911b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 330262, 999065
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1774627Reviewed-by: Oskar Sundbom <ossu@chromium.org>
Commit-Queue: Oskar Sundbom <ossu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691542}

base/BUILD.gn

@@ -2071,8 +2071,6 @@ buildflag_header("debugging_buildflags") {
   header_dir = "base/debug"
   enable_gdbinit_warning =
       is_debug && (strip_absolute_paths_from_debug_symbols || use_custom_libcxx)
-  enable_lldbinit_warning =
-      is_debug && strip_absolute_paths_from_debug_symbols && is_mac
 
   flags = [
     "ENABLE_LOCATION_SOURCE=$enable_location_source",
@@ -2081,7 +2079,6 @@ buildflag_header("debugging_buildflags") {
     "UNSAFE_DEVELOPER_BUILD=$is_unsafe_developer_build",
     "CAN_UNWIND_WITH_CFI_TABLE=$can_unwind_with_cfi_table",
     "ENABLE_GDBINIT_WARNING=$enable_gdbinit_warning",
-    "ENABLE_LLDBINIT_WARNING=$enable_lldbinit_warning",
   ]
 }
 

base/debug/debugger.h

@@ -40,8 +40,7 @@ BASE_EXPORT bool IsDebugUISuppressed();
 
 // If a debugger is present, verifies that it is properly set up, and DCHECK()s
 // if misconfigured.  Currently only verifies that //tools/gdb/gdbinit has been
-// sourced when using gdb on Linux and //tools/lldb/lldbinit.py has been sourced
-// when using lldb on macOS.
+// sourced when using gdb on Linux.
 BASE_EXPORT void VerifyDebugger();
 
 }  // namespace debug

base/debug/debugger_posix.cc

@@ -128,21 +128,7 @@ bool BeingDebugged() {
   return being_debugged;
 }
 
-void VerifyDebugger() {
-#if BUILDFLAG(ENABLE_LLDBINIT_WARNING)
-  // Quick check before potentially slower GetDebuggerProcess().
-  if (Environment::Create()->HasVar("CHROMIUM_LLDBINIT_SOURCED"))
-    return;
-  DCHECK(false)
-      << "Detected lldb without sourcing //tools/lldb/lldbinit.py. lldb may "
-         "not be able to find debug symbols. Please see debug instructions for "
-         "using //tools/lldb/lldbinit.py:\n"
-         "https://chromium.googlesource.com/chromium/src/+/master/docs/"
-         "lldbinit.md\n"
-         "To continue anyway, type 'continue' in lldb. To always skip this "
-         "check, define an environment variable CHROMIUM_LLDBINIT_SOURCED=1";
-#endif
-}
+void VerifyDebugger() {}
 
 #elif defined(OS_LINUX) || defined(OS_ANDROID) || defined(OS_AIX)
 

docs/lldbinit.md

-# Usage of tools/lldb/lldbinit.py
-
-Usage of Chromium's [lldbinit.py](../tools/lldb/lldbinit.py) is recommended when
-debugging with lldb. This is necessary for source-level debugging when
-`strip_absolute_paths_from_debug_symbols` is enabled.
-
-To use, add the following to your `~/.lldbinit`
-
-```
-# So that lldbinit.py takes precedence.
-script sys.path[:0] = ['<.../path/to/chromium/src/tools/lldb>']
-script import lldbinit
-```

tools/lldb/lldbinit.py

-# Copyright 2019 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# The GN arg `strip_absolute_paths_from_debug_symbols = 1` uses relative paths
-# for debug symbols. This confuses lldb. We explicitly set the source-map to
-# point at the root directory of the chromium checkout.
-import os
-import lldb
-this_dir = os.path.dirname(os.path.abspath(__file__))
-source_dir = os.path.join(os.path.join(this_dir, os.pardir), os.pardir)
-
-lldb.debugger.HandleCommand(
-    'settings set target.source-map ../.. ' + source_dir)
-lldb.debugger.HandleCommand(
-    'settings set target.env-vars CHROMIUM_LLDBINIT_SOURCED=1')