Remove som GYP annotations, remove unused manifest.

android_webview/tools/system_webview_shell/BUILD.gn

 # Copyright 2015 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.
 
 import("//build/config/android/rules.gni")
 import("//testing/test.gni")
 
 # Mark all targets as test only.
 testonly = true
 
 group("system_webview_shell") {
   deps = [
     ":system_webview_shell_apk",
     ":system_webview_shell_layout_test_apk",
     ":system_webview_shell_page_cycler_apk",
   ]
 }
 
-# GYP: //android_webview/android_webview_shell.gypi:system_webview_shell_apk
 android_apk("system_webview_shell_apk") {
   apk_name = "SystemWebViewShell"
   java_files = [
     "apk/src/org/chromium/webview_shell/JankActivity.java",
     "apk/src/org/chromium/webview_shell/PageCyclerTestActivity.java",
     "apk/src/org/chromium/webview_shell/StartupTimeActivity.java",
     "apk/src/org/chromium/webview_shell/TelemetryActivity.java",
     "apk/src/org/chromium/webview_shell/TelemetryMemoryPressureActivity.java",
     "apk/src/org/chromium/webview_shell/WebViewCreateDestroyActivity.java",
     "apk/src/org/chromium/webview_shell/WebViewBrowserActivity.java",
     "apk/src/org/chromium/webview_shell/WebViewLayoutTestActivity.java",
     "apk/src/org/chromium/webview_shell/WebViewThreadTestActivity.java",
   ]
   android_manifest = "apk/AndroidManifest.xml"
   deps = [
     ":system_webview_shell_apk_resources",
     "//base:base_java",
   ]
 }
 
 android_resources("system_webview_shell_apk_resources") {
   resource_dirs = [ "apk/res" ]
   custom_package = "org.chromium.webview_shell"
 }
 
-# GYP: //android_webview/android_webview_shell.gypi:system_webview_shell_page_cycler_apk
 instrumentation_test_apk("system_webview_shell_page_cycler_apk") {
   apk_name = "SystemWebViewShellPageCycler"
   apk_under_test = ":system_webview_shell_apk"
   android_manifest = "page_cycler/AndroidManifest.xml"
   java_files = [
     "page_cycler/src/org/chromium/webview_shell/page_cycler/PageCyclerTest.java",
     "page_cycler/src/org/chromium/webview_shell/page_cycler/WebViewPageCyclerTestRunner.java",
   ]
   deps = [
     "//base:base_java",
     "//base:base_java_test_support",
     "//content/public/android:content_java",
     "//content/public/test/android:content_java_test_support",
     "//testing/android/reporter:reporter_java",
   ]
 }
 
-# GYP: //android_webview/android_webview_shell.gypi:system_webview_shell_layout_test_apk
 instrumentation_test_apk("system_webview_shell_layout_test_apk") {
   apk_name = "SystemWebViewShellLayoutTest"
   apk_under_test = ":system_webview_shell_apk"
   android_manifest = "layout_tests/AndroidManifest.xml"
   java_files = [
     "layout_tests/src/org/chromium/webview_shell/test/WebViewLayoutTest.java",
     "layout_tests/src/org/chromium/webview_shell/test/WebViewLayoutTestRunner.java",
     "layout_tests/src/org/chromium/webview_shell/test/WebViewThreadTest.java",
   ]
   deps = [
     "//base:base_java",
     "//base:base_java_test_support",
     "//testing/android/reporter:reporter_java",
   ]
   data = [
     "test/data/",
     "//third_party/WebKit/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt",
     "//third_party/WebKit/LayoutTests/webexposed/global-interface-listing.html",
     "//third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt",
     "//third_party/WebKit/LayoutTests/webexposed/resources/global-interface-listing.js",
   ]
 }