Prevent the screen from sleeping when the desktop is being captured.

content/browser/media/capture/desktop_capture_device_aura.cc

 // Copyright 2013 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.
 
 #include "content/browser/media/capture/desktop_capture_device_aura.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/timer/timer.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
 #include "content/browser/compositor/image_transport_factory.h"
 #include "content/browser/media/capture/content_video_capture_device_core.h"
 #include "content/browser/media/capture/desktop_capture_device_uma_types.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/power_save_blocker.h"
 #include "media/base/video_util.h"
 #include "media/video/capture/video_capture_types.h"
 #include "skia/ext/image_operations.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/cursor/cursors_aura.h"
@@ skipping 140 matching lines @@
   media::VideoCaptureParams capture_params_;
 
   // YUV readback pipeline.
   scoped_ptr<content::ReadbackYUVInterface> yuv_readback_pipeline_;
 
   // Cursor state.
   ui::Cursor last_cursor_;
   gfx::Point cursor_hot_point_;
   SkBitmap scaled_cursor_bitmap_;
 
+  scoped_ptr<PowerSaveBlocker> power_save_blocker_;
+
   DISALLOW_COPY_AND_ASSIGN(DesktopVideoCaptureMachine);
 };
 
 DesktopVideoCaptureMachine::DesktopVideoCaptureMachine(
     const DesktopMediaID& source)
     : desktop_window_(NULL),
       timer_(true, true),
       window_id_(source) {}
 
 DesktopVideoCaptureMachine::~DesktopVideoCaptureMachine() {}
@@ skipping 19 matching lines @@
   // Update capture size.
   UpdateCaptureSize();
 
   // Start observing window events.
   desktop_window_->AddObserver(this);
 
   // Start observing compositor updates.
   if (desktop_window_->GetHost())
     desktop_window_->GetHost()->compositor()->AddObserver(this);
 
+  power_save_blocker_.reset(PowerSaveBlocker::Create(
+      PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep,
+      "DesktopCatureDevice is running").release());
+
   // Starts timer.
   timer_.Start(FROM_HERE, oracle_proxy_->min_capture_period(),
                base::Bind(&DesktopVideoCaptureMachine::Capture, AsWeakPtr(),
                           false));
 
   started_ = true;
   return true;
 }
 
 void DesktopVideoCaptureMachine::Stop(const base::Closure& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  power_save_blocker_.reset();
 
   // Stop observing compositor and window events.
   if (desktop_window_) {
     if (desktop_window_->GetHost())
       desktop_window_->GetHost()->compositor()->RemoveObserver(this);
     desktop_window_->RemoveObserver(this);
     desktop_window_ = NULL;
   }
 
   // Stop timer.
@@ skipping 292 matching lines @@
     scoped_ptr<Client> client) {
   DVLOG(1) << "Allocating " << params.requested_format.frame_size.ToString();
   core_->AllocateAndStart(params, client.Pass());
 }
 
 void DesktopCaptureDeviceAura::StopAndDeAllocate() {
   core_->StopAndDeAllocate();
 }
 
 }  // namespace content