[Chromecast] Clean up avsync media shlib dependencies

Bug: internal b/132246481
Change-Id: I143361405972a488158eff162a9f5c4fd3a97544
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1602872Reviewed-by: Sergey Volk <servolk@chromium.org>
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659388}

chromecast/media/cma/backend/video/BUILD.gn

@@ -37,6 +37,7 @@ cast_source_set("cast_media_shlib_common") {
     "cast_media_shlib_common.cc",
   ]
   deps = [
+    "//base",
     "//chromecast/public/media",
   ]
 }
@@ -59,7 +60,6 @@ cast_shared_library("libcast_media_1.0_avsync") {
   deps = [
     ":av_sync_video",
     ":cast_media_shlib_default",
-    ":task_runner_lifetime_handler",
     "//chromecast/base:base",
     "//chromecast/media/cma/backend:for_mixer_audio",
     "//chromecast/public/media",

chromecast/media/cma/backend/video/cast_media_shlib_common.cc

@@ -2,11 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/at_exit.h"
 #include "chromecast/public/media/media_capabilities_shlib.h"
 
 namespace chromecast {
 namespace media {
 
+namespace {
+base::AtExitManager g_at_exit_manager;
+}  // namespace
+
 bool MediaCapabilitiesShlib::IsSupportedAudioConfig(const AudioConfig& config) {
   switch (config.codec) {
     case kCodecPCM:

chromecast/media/cma/backend/video/task_runner_lifetime_handler.cc

@@ -4,7 +4,6 @@
 
 #include "chromecast/media/cma/backend/video/task_runner_lifetime_handler.h"
 
-#include "base/at_exit.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -13,7 +12,6 @@
 namespace chromecast {
 namespace media {
 
-base::AtExitManager g_at_exit_manager;
 std::unique_ptr<base::ThreadTaskRunnerHandle> g_thread_task_runner_handle;
 
 // static