Move ScreenCapturer 'real' tests out of screen_capturer_unittest.cc.

webrtc/modules/desktop_capture/screen_drawer_linux.cc

 /*
  *  Copyright (c) 2016 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.
  */
 
@@ skipping 12 matching lines @@
 namespace webrtc {
 
 namespace {
 
 static constexpr char kSemaphoreName[] =
     "/global-screen-drawer-linux-54fe5552-8047-11e6-a725-3f429a5b4fb4";
 
 class ScreenDrawerLockLinux : public ScreenDrawerLock {
  public:
   ScreenDrawerLockLinux();
-  ~ScreenDrawerLockLinux();
+  ~ScreenDrawerLockLinux() override;
 
  private:
   sem_t* semaphore_;
 };
 
 ScreenDrawerLockLinux::ScreenDrawerLockLinux() {
   semaphore_ =
       sem_open(kSemaphoreName, O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO, 1);
   sem_wait(semaphore_);
 }
@@ skipping 147 matching lines @@
 
 // static
 std::unique_ptr<ScreenDrawer> ScreenDrawer::Create() {
   if (SharedXDisplay::CreateDefault().get()) {
     return std::unique_ptr<ScreenDrawer>(new ScreenDrawerLinux());
   }
   return nullptr;
 }
 
 }  // namespace webrtc