VideoCaptureParams: add flag for hinting capture using GpuMemoryBuffers & flag for it

media/base/media_switches.cc

 // Copyright (c) 2012 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 "media/base/media_switches.h"
 
 namespace switches {
 
 // Allow users to specify a custom buffer size for debugging purpose.
 const char kAudioBufferSize[] = "audio-buffer-size";
@@ skipping 10 matching lines @@
     "enable-media-thread-for-media-playback";
 #endif
 
 #if defined(OS_LINUX) || defined(OS_FREEBSD) || defined(OS_SOLARIS)
 // The Alsa device to use when opening an audio input stream.
 const char kAlsaInputDevice[] = "alsa-input-device";
 // The Alsa device to use when opening an audio stream.
 const char kAlsaOutputDevice[] = "alsa-output-device";
 #endif
 
+#if defined(OS_LINUX)
+// Try to use Native GpuMemoryBuffers for Video Capture. The actual use depends
+// on the actual hardware capabilities of the capture device and encoder(s).
+const char kUseNativeGpuMemoryBuffersForCapture[] =
+    "use-native-gpu-memory-buffers-for-capture";
+#endif
+
 #if defined(OS_MACOSX)
 // AVFoundation is available in versions 10.7 and onwards, and is to be used
 // http://crbug.com/288562 for both audio and video device monitoring and for
 // video capture. Being a dynamically loaded NSBundle and library, it hits the
 // Chrome startup time (http://crbug.com/311325 and http://crbug.com/311437);
 // for experimentation purposes, in particular library load time issue, the
 // usage of this library can be enabled by using this flag.
 const char kEnableAVFoundation[] = "enable-avfoundation";
 
 // QTKit is the media capture API predecessor to AVFoundation, available up and
@@ skipping 67 matching lines @@
 // this flag will cause the tests to fail. Otherwise, they silently succeed.
 const char kRequireAudioHardwareForTesting[] =
     "require-audio-hardware-for-testing";
 
 // Allows clients to override the threshold for when the media renderer will
 // declare the underflow state for the video stream when audio is present.
 // TODO(dalecurtis): Remove once experiments for http://crbug.com/470940 finish.
 const char kVideoUnderflowThresholdMs[] = "video-underflow-threshold-ms";
 
 }  // namespace switches