Revert "Add -Wl,--allow-shlib-undefined to some executables."

This reverts commit e4dbb92e.

Reason for revert: Should no longer be needed after sysroot roll:
https://chromium-review.googlesource.com/c/chromium/src/+/2219606

Original change's description:
> Add -Wl,--allow-shlib-undefined to some executables.
> 
> Due to https://reviews.llvm.org/D80059, a hack for unversioned libdbus symbols
> no longer works. This adds --allow-shlib-undefined for the dependent
> executables when llvm_force_head_revision is enabled to green the ToT bots.
> 
> Bug: 1086636
> Change-Id: I78a5d1a56953c1a5cb5694f299080bdeee0726d2
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2220350
> Commit-Queue: Amy Huang <akhuang@google.com>
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#772912}

TBR=thakis@chromium.org,akhuang@google.com

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

Bug: 1086636
Change-Id: I3e9bcea3eea6e881f66b4822e2750d1fccdd4516
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2223011Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773436}

components/metrics/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//build/config/jumbo.gni")
 import("//testing/test.gni")
 
@@ -522,9 +521,4 @@ test("metrics_unittests") {
     ":unit_tests",
     "//components/test:test_support",
   ]
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }

components/mirroring/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//testing/test.gni")
 
 group("mirroring_tests") {
@@ -18,9 +17,4 @@ test("mirroring_unittests") {
     ":mirroring_tests",
     "//media/test:run_all_unittests",
   ]
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }

components/paint_preview/browser/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//testing/test.gni")
 
 assert(!is_ios, "Paint Previews are not supported on iOS.")
@@ -107,9 +106,4 @@ test("paint_preview_browser_unit_tests") {
     "//base/test:test_support",
     "//components/test:run_all_unittests",
   ]
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }

components/paint_preview/common/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//testing/test.gni")
 
 if (!is_ios) {
@@ -76,10 +75,5 @@ if (!is_ios) {
       "//base/test:test_support",
       "//components/test:run_all_unittests",
     ]
-
-    # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-    if (llvm_force_head_revision && is_linux && !is_chromeos) {
-      ldflags = [ "-Wl,--allow-shlib-undefined" ]
-    }
   }
 }

components/paint_preview/renderer/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//testing/test.gni")
 
 if (!is_ios) {
@@ -51,10 +50,5 @@ if (!is_ios) {
       "//base/test:test_support",
       "//components/test:run_all_unittests",
     ]
-
-    # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-    if (llvm_force_head_revision && is_linux && !is_chromeos) {
-      ldflags = [ "-Wl,--allow-shlib-undefined" ]
-    }
   }
 }

components/rappor/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//build/config/jumbo.gni")
 import("//testing/test.gni")
 
@@ -100,9 +99,4 @@ test("rappor_unittests") {
     ":unit_tests",
     "//components/test:test_support",
   ]
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }

components/variations/BUILD.gn

@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/clang/clang.gni")
 import("//testing/test.gni")
 
 if (is_android) {
@@ -173,9 +172,4 @@ test("variations_unittests") {
     "//components/variations/field_trial_config:unit_tests",
     "//components/variations/service:unit_tests",
   ]
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }

content/test/BUILD.gn

@@ -2451,11 +2451,6 @@ test("content_perftests") {
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
   }
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }
 
 group("fuzzers") {

third_party/blink/renderer/controller/BUILD.gn

@@ -135,11 +135,6 @@ test("blink_unittests") {
 
 test("blink_perf_tests") {
   deps = [ ":blink_perf_tests_sources" ]
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (llvm_force_head_revision && is_linux && !is_chromeos) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }
 
 jumbo_source_set("blink_perf_tests_sources") {

tools/accessibility/inspect/BUILD.gn

@@ -38,9 +38,4 @@ executable("ax_dump_tree") {
   if (is_win) {
     libs = [ "oleacc.lib" ]
   }
-
-  # TODO(https://crbug/1086636): Remove when the libdbus hack is removed.
-  if (is_linux) {
-    ldflags = [ "-Wl,--allow-shlib-undefined" ]
-  }
 }