Revert "Add GN Build file for rtc_sound target."

This reverts commit f054819e257a4f9cbb7fa82ba51dc2335f4359ec,
2d3747de9b7c3014e106d3766dc07cf5da3e1881 and
7ef0553c85c5b373535d7f6161e9a6d3b5b9a826.
It seems harder than expected to get a GN build for rtc_sound
and we lack sufficient trybot support for the case where
WebRTC is built as part of Chromium.

The Debug builds failed like this:
[6939/7454] SOLINK ./libcontent.so
FAILED: ../../third_party/llvm-build/Release+Asserts/bin/clang++ -shared -Wl,--fatal-warnings -fPIC -Wl,-z,noexecstack -Wl,-z,now -Wl,-z,relro -Wl,-z,defs -B../../third_party/binutils/Linux_x64/Release/bin -fuse-ld=gold -Wl,--icf=all -pthread -m64 -Wl,--export-dynamic -o ./libcontent.so -Wl,-soname=libcontent.so @./libcontent.so.rsp && { readelf -d ./libcontent.so | grep SONAME ; nm -gD -f p ./libcontent.so | cut -f1-2 -d' '; } > ./libcontent.so.tmp && if ! cmp -s ./libcontent.so.tmp ./libcontent.so.TOC; then mv ./libcontent.so.tmp ./libcontent.so.TOC; fi
../../third_party/webrtc/sound/alsasoundsystem.cc:453: error: undefined reference to 'rtc::LateBindingSymbolTable::Load()'
../../third_party/webrtc/base/latebindingsymboltable.h.def:62: error: undefined reference to 'rtc::LateBindingSymbolTable::IsLoaded() const'
../../third_party/webrtc/base/latebindingsymboltable.h.def:62: error: undefined reference to 'rtc::LateBindingSymbolTable::IsLoaded() const'
../../third_party/webrtc/base/latebindingsymboltable.h.def:62: error: undefined reference to 'rtc::LateBindingSymbolTable::IsLoaded() const'
../../third_party/webrtc/base/latebindingsymboltable.h.def:62: error: undefined reference to 'rtc::LateBindingSymbolTable::IsLoaded() const'
../../third_party/webrtc/base/latebindingsymboltable.cc.def:63: error: undefined reference to 'rtc::LateBindingSymbolTable::LateBindingSymbolTable(rtc::LateBindingSymbolTable::TableInfo const*, void**)'
../../third_party/webrtc/base/latebindingsymboltable.cc.def:65: error: undefined reference to 'rtc::LateBindingSymbolTable::~LateBindingSymbolTable()'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.

BUG=webrtc:4160
TBR=tfarina@chromium.org

Review URL: https://codereview.webrtc.org/1407893005 .

Cr-Commit-Position: refs/heads/master@{#10411}
diff --git a/webrtc/BUILD.gn b/webrtc/BUILD.gn
index c8b7ea0..ac14d7d 100644
--- a/webrtc/BUILD.gn
+++ b/webrtc/BUILD.gn
@@ -178,8 +178,8 @@
   public_configs = [ ":common_inherited_config" ]
 
   deps = [
-    ":webrtc_common",
     "audio",
+    ":webrtc_common",
     "base:rtc_base",
     "call",
     "common_audio",
@@ -195,7 +195,6 @@
     "modules/utility",
     "modules/video_coding",
     "modules/video_processing",
-    "sound:rtc_sound",
     "system_wrappers",
     "tools",
     "video",
diff --git a/webrtc/sound/BUILD.gn b/webrtc/sound/BUILD.gn
deleted file mode 100644
index 43decf8..0000000
--- a/webrtc/sound/BUILD.gn
+++ /dev/null
@@ -1,58 +0,0 @@
-# Copyright 2015 The WebRTC project authors. All Rights Reserved.
-#
-# Use of this source code is governed by a BSD-style license
-# that can be found in the LICENSE file in the root of the source
-# tree. An additional intellectual property rights grant can be found
-# in the file PATENTS.  All contributing project authors may
-# be found in the AUTHORS file in the root of the source tree.
-import("../build/webrtc.gni")
-
-static_library("rtc_sound") {
-  sources = [
-    "automaticallychosensoundsystem.h",
-    "nullsoundsystem.cc",
-    "nullsoundsystem.h",
-    "nullsoundsystemfactory.cc",
-    "nullsoundsystemfactory.h",
-    "platformsoundsystem.cc",
-    "platformsoundsystem.h",
-    "platformsoundsystemfactory.cc",
-    "platformsoundsystemfactory.h",
-    "sounddevicelocator.h",
-    "soundinputstreaminterface.h",
-    "soundoutputstreaminterface.h",
-    "soundsystemfactory.h",
-    "soundsysteminterface.cc",
-    "soundsysteminterface.h",
-    "soundsystemproxy.cc",
-    "soundsystemproxy.h",
-  ]
-
-  configs += [ "..:common_config" ]
-  public_configs = [ "..:common_inherited_config" ]
-
-  if (is_clang) {
-    # Suppress warnings from Chrome's Clang plugins.
-    # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
-    configs -= [ "//build/config/clang:find_bad_constructs" ]
-  }
-
-  deps = [
-    "../base:rtc_base",
-  ]
-
-  if (is_linux) {
-    sources += [
-      "alsasoundsystem.cc",
-      "alsasoundsystem.h",
-      "alsasymboltable.cc",
-      "alsasymboltable.h",
-      "linuxsoundsystem.cc",
-      "linuxsoundsystem.h",
-      "pulseaudiosoundsystem.cc",
-      "pulseaudiosoundsystem.h",
-      "pulseaudiosymboltable.cc",
-      "pulseaudiosymboltable.h",
-    ]
-  }
-}