Add switch for enabling GpuMemoryBuffer-based video capture buffer

This CL adds a switch to selectively enable GpuMemoryBuffer-based video
capture buffer. Devices supporting GMB-based video capture buffers can
achieve zero-copy for camera preview and reduce the power consumption on
various use cases significantly.

Design doc: go/cros-camera:dd:zero-copy

      /etc/chrome_dev.conf on Nocturne, and verify everything works.

Bug: 982201
Test: Manually add "--video-capture-use-gpu-memory-buffer" into
Change-Id: I178e00b0400e01f32ff8605de60c6dc2364dd384
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1692155Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Commit-Queue: Ricky Liang <jcliang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#698872}

chrome/browser/chromeos/login/chrome_restart_request.cc

@@ -151,6 +151,7 @@ void DeriveCommandLine(const GURL& start_url,
     ::switches::kUserDataDir,
     ::switches::kV,
     ::switches::kVModule,
+    ::switches::kVideoCaptureUseGpuMemoryBuffer,
     ::switches::kEnableWebGLDraftExtensions,
     ::switches::kDisableWebGLImageChromium,
     ::switches::kEnableWebGLImageChromium,

content/browser/renderer_host/media/service_video_capture_device_launcher.cc

@@ -8,10 +8,12 @@
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/command_line.h"
 #include "base/task/post_task.h"
 #include "content/browser/renderer_host/media/service_launched_video_capture_device.h"
 #include "content/public/browser/browser_task_traits.h"
 #include "content/public/browser/browser_thread.h"
+#include "media/base/media_switches.h"
 #include "media/capture/video/video_capture_device.h"
 #include "media/capture/video/video_frame_receiver_on_task_runner.h"
 #include "mojo/public/cpp/bindings/pending_remote.h"
@@ -136,6 +138,17 @@ void ServiceVideoCaptureDeviceLauncher::LaunchDeviceAsync(
   new_params.power_line_frequency =
       media::VideoCaptureDevice::GetPowerLineFrequency(params);
 
+  // GpuMemoryBuffer-based VideoCapture buffer works only on the Chrome OS
+  // VideoCaptureDevice implementation. It's not supported by
+  // FakeVideoCaptureDevice.
+  // TODO: Support GpuMemoryBuffer in FakeVideoCaptureDevice (crbug.com/1006613)
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kVideoCaptureUseGpuMemoryBuffer) &&
+      !base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseFakeDeviceForMediaStream)) {
+    new_params.buffer_type = media::VideoCaptureBufferType::kGpuMemoryBuffer;
+  }
+
   // Note that we set |force_reopen_with_new_settings| to true in order
   // to avoid the situation that a requests to open (or reopen) a device
   // that has just been closed with different settings ends up getting the old

media/base/media_switches.cc

@@ -167,6 +167,10 @@ const char kOverrideEnabledCdmInterfaceVersion[] =
 const char kOverrideHardwareSecureCodecsForTesting[] =
     "override-hardware-secure-codecs-for-testing";
 
+// Enables GpuMemoryBuffer-based buffer pool.
+const char kVideoCaptureUseGpuMemoryBuffer[] =
+    "video-capture-use-gpu-memory-buffer";
+
 namespace autoplay {
 
 // Autoplay policy that requires a document user activation.

media/base/media_switches.h

@@ -78,6 +78,8 @@ MEDIA_EXPORT extern const char kClearKeyCdmPathForTesting[];
 MEDIA_EXPORT extern const char kOverrideEnabledCdmInterfaceVersion[];
 MEDIA_EXPORT extern const char kOverrideHardwareSecureCodecsForTesting[];
 
+MEDIA_EXPORT extern const char kVideoCaptureUseGpuMemoryBuffer[];
+
 namespace autoplay {
 
 MEDIA_EXPORT extern const char kDocumentUserActivationRequiredPolicy[];

services/video_capture/device_media_to_mojo_adapter.cc

@@ -5,8 +5,10 @@
 #include "services/video_capture/device_media_to_mojo_adapter.h"
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "media/base/bind_to_current_loop.h"
+#include "media/base/media_switches.h"
 #include "media/capture/video/video_capture_buffer_pool_impl.h"
 #include "media/capture/video/video_capture_buffer_tracker_factory_impl.h"
 #include "media/capture/video/video_frame_receiver_on_task_runner.h"
@@ -74,6 +76,8 @@ void DeviceMediaToMojoAdapter::Start(
 
   if (requested_settings.buffer_type !=
           media::VideoCaptureBufferType::kSharedMemory &&
+      requested_settings.buffer_type !=
+          media::VideoCaptureBufferType::kGpuMemoryBuffer &&
       requested_settings.buffer_type !=
           media::VideoCaptureBufferType::kSharedMemoryViaRawFileDescriptor) {
     // Buffer types other than shared memory are not supported.
@@ -170,7 +174,18 @@ int DeviceMediaToMojoAdapter::max_buffer_pool_buffer_count() {
   // The maximum number of video frame buffers in-flight at any one time.
   // If all buffers are still in use by consumers when new frames are produced
   // those frames get dropped.
-  static const int kMaxBufferCount = 3;
+  static int kMaxBufferCount = 3;
+
+#if defined(OS_CHROMEOS)
+  // On Chrome OS with MIPI cameras running on HAL v3, there can be three
+  // concurrent streams of camera pipeline depth ~6. We allow at most 24 buffers
+  // here to take into account the delay caused by the consumer (e.g. display or
+  // video encoder).
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kVideoCaptureUseGpuMemoryBuffer)) {
+    kMaxBufferCount = 24;
+  }
+#endif
 
   return kMaxBufferCount;
 }