Check for use_x11 before runnig desktop_capture_modules_tests on linux.

webrtc/modules/desktop_capture/BUILD.gn

 # Copyright (c) 2014 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/config/ui.gni")
 import("../../webrtc.gni")
@@ skipping 39 matching lines @@
       ]
       sources += [
         "screen_capturer_integration_test.cc",
         "screen_drawer_unittest.cc",
       ]
     }
   }
 
   rtc_source_set("desktop_capture_unittests") {
     testonly = true
-    sources = []
-    deps = []
-    if (rtc_desktop_capture_supported || is_android) {
-      deps += [
-        ":desktop_capture",
-        ":primitives",
-        "../..:webrtc_common",
-        "../../base:rtc_base_approved",
-        "../../system_wrappers:system_wrappers",
-        "../../test:test_support",
-        "//testing/gmock",
-      ]
-      sources += [
-        "desktop_region_unittest.cc",
-        "differ_block_unittest.cc",
-      ]
-    }
+    sources = [
+      "desktop_and_cursor_composer_unittest.cc",
+      "desktop_capturer_differ_wrapper_unittest.cc",
+      "desktop_frame_rotation_unittest.cc",
+      "desktop_region_unittest.cc",
+      "differ_block_unittest.cc",
+      "mouse_cursor_monitor_unittest.cc",
+      "rgba_color_unittest.cc",
+      "test_utils.cc",
+      "test_utils.h",
+      "test_utils_unittest.cc",
+      "win/cursor_unittest.cc",
+      "win/cursor_unittest_resources.h",
+      "win/cursor_unittest_resources.rc",
+    ]
+    deps = [
+      ":desktop_capture",
+      ":desktop_capture_mock",
+      ":primitives",
+      ":rgba_color",
+      "../..:webrtc_common",
+      "../../base:rtc_base_approved",
+      "../../system_wrappers:system_wrappers",
+      "../../test:test_support",
+      "//testing/gmock",
+    ]
     if (rtc_desktop_capture_supported) {
       sources += [
-        "desktop_and_cursor_composer_unittest.cc",
-        "desktop_capturer_differ_wrapper_unittest.cc",
-        "desktop_frame_rotation_unittest.cc",
-        "mouse_cursor_monitor_unittest.cc",
-        "rgba_color_unittest.cc",
         "screen_capturer_helper_unittest.cc",
         "screen_capturer_mac_unittest.cc",
         "screen_capturer_unittest.cc",
-        "test_utils.cc",
-        "test_utils.h",
-        "test_utils_unittest.cc",
-        "win/cursor_unittest.cc",
-        "win/cursor_unittest_resources.h",
-        "win/cursor_unittest_resources.rc",
         "window_capturer_unittest.cc",
       ]
       deps += [ ":desktop_capture_mock" ]
     }
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 
@@ skipping 198 matching lines @@
     sources = [
       "differ_vector_sse2.cc",
       "differ_vector_sse2.h",
     ]
 
     if (is_posix) {
       cflags = [ "-msse2" ]
     }
   }
 }