[Video Capture, Chrome OS]: add camera profiling tool

I add a tracing tool in ChromeOS, and this is the Chrome side code to
interact with the hal_adapter in ChromeOS through mojo. Also add the
tracing of the camera capture request and get result.

CQ-DEPEND=CL:1158095
BUG=b:109714458
TEST=Open about://tracing in Chrome, click Record, and choose CrosCamera.
Open any camera app, and close it. Click Stop button in Chrome, and there
will have some events show on the UI. In the process of camera service, and
if you open the camera in chrome the browser process will also have some
events.
TEST=Pass capture_unittests

Change-Id: I1ae67b8ca49d63679228eea5b579818b0b3d3686
Reviewed-on: https://chromium-review.googlesource.com/1158106
Commit-Queue: Jyun-jhe Chou <hobexd@google.com>
Reviewed-by: Ricky Liang <jcliang@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589120}

media/capture/video/chromeos/camera_device_delegate.cc

@@ -11,6 +11,7 @@
 
 #include "base/numerics/ranges.h"
 #include "base/posix/safe_strerror.h"
+#include "base/trace_event/trace_event.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/capture/mojom/image_capture_types.h"
 #include "media/capture/video/blob_utils.h"
@@ -619,6 +620,10 @@ void CameraDeviceDelegate::ProcessCaptureRequest(
     cros::mojom::Camera3CaptureRequestPtr request,
     base::OnceCallback<void(int32_t)> callback) {
   DCHECK(ipc_task_runner_->BelongsToCurrentThread());
+  for (const auto& output_buffer : request->output_buffers) {
+    TRACE_EVENT2("camera", "Capture Request", "frame_number",
+                 request->frame_number, "stream_id", output_buffer->stream_id);
+  }
 
   if (device_context_->GetState() != CameraDeviceContext::State::kCapturing) {
     DCHECK_EQ(device_context_->GetState(),

media/capture/video/chromeos/camera_hal_dispatcher_impl.cc

@@ -18,6 +18,7 @@
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/trace_event/trace_event.h"
 #include "mojo/public/cpp/platform/named_platform_channel.h"
 #include "mojo/public/cpp/platform/platform_channel.h"
 #include "mojo/public/cpp/platform/socket_utils_posix.h"
@@ -155,7 +156,11 @@ bool CameraHalDispatcherImpl::IsStarted() {
 
 CameraHalDispatcherImpl::CameraHalDispatcherImpl()
     : proxy_thread_("CameraProxyThread"),
-      blocking_io_thread_("CameraBlockingIOThread") {}
+      blocking_io_thread_("CameraBlockingIOThread") {
+  // This event is for adding camera category to categories list.
+  TRACE_EVENT0("camera", "CameraHalDispatcherImpl");
+  base::trace_event::TraceLog::GetInstance()->AddEnabledStateObserver(this);
+}
 
 CameraHalDispatcherImpl::~CameraHalDispatcherImpl() {
   VLOG(1) << "Stopping CameraHalDispatcherImpl...";
@@ -166,6 +171,7 @@ CameraHalDispatcherImpl::~CameraHalDispatcherImpl() {
     proxy_thread_.Stop();
   }
   blocking_io_thread_.Stop();
+  base::trace_event::TraceLog::GetInstance()->RemoveEnabledStateObserver(this);
   VLOG(1) << "CameraHalDispatcherImpl stopped";
 }
 
@@ -212,6 +218,20 @@ void CameraHalDispatcherImpl::GetJpegEncodeAccelerator(
   jea_factory_.Run(std::move(jea_request));
 }
 
+void CameraHalDispatcherImpl::OnTraceLogEnabled() {
+  proxy_task_runner_->PostTask(
+      FROM_HERE,
+      base::BindOnce(&CameraHalDispatcherImpl::OnTraceLogEnabledOnProxyThread,
+                     base::Unretained(this)));
+}
+
+void CameraHalDispatcherImpl::OnTraceLogDisabled() {
+  proxy_task_runner_->PostTask(
+      FROM_HERE,
+      base::BindOnce(&CameraHalDispatcherImpl::OnTraceLogDisabledOnProxyThread,
+                     base::Unretained(this)));
+}
+
 void CameraHalDispatcherImpl::CreateSocket(base::WaitableEvent* started) {
   DCHECK(blocking_io_task_runner_->BelongsToCurrentThread());
 
@@ -381,4 +401,24 @@ void CameraHalDispatcherImpl::StopOnProxyThread() {
   binding_set_.CloseAllBindings();
 }
 
+void CameraHalDispatcherImpl::OnTraceLogEnabledOnProxyThread() {
+  DCHECK(proxy_task_runner_->BelongsToCurrentThread());
+  if (!camera_hal_server_) {
+    return;
+  }
+  bool camera_event_enabled = false;
+  TRACE_EVENT_CATEGORY_GROUP_ENABLED("camera", &camera_event_enabled);
+  if (camera_event_enabled) {
+    camera_hal_server_->SetTracingEnabled(true);
+  }
+}
+
+void CameraHalDispatcherImpl::OnTraceLogDisabledOnProxyThread() {
+  DCHECK(proxy_task_runner_->BelongsToCurrentThread());
+  if (!camera_hal_server_) {
+    return;
+  }
+  camera_hal_server_->SetTracingEnabled(false);
+}
+
 }  // namespace media

media/capture/video/chromeos/camera_hal_dispatcher_impl.h

@@ -44,7 +44,8 @@ class CAPTURE_EXPORT CameraClientObserver {
 // For general documentation about the CameraHalDispater Mojo interface see the
 // comments in mojo/cros_camera_service.mojom.
 class CAPTURE_EXPORT CameraHalDispatcherImpl final
-    : public cros::mojom::CameraHalDispatcher {
+    : public cros::mojom::CameraHalDispatcher,
+      public base::trace_event::TraceLog::EnabledStateObserver {
  public:
   static CameraHalDispatcherImpl* GetInstance();
 
@@ -63,6 +64,10 @@ class CAPTURE_EXPORT CameraHalDispatcherImpl final
   void GetJpegEncodeAccelerator(
       media::mojom::JpegEncodeAcceleratorRequest jea_request) final;
 
+  // base::trace_event::TraceLog::EnabledStateObserver implementation.
+  void OnTraceLogEnabled() final;
+  void OnTraceLogDisabled() final;
+
  private:
   friend struct base::DefaultSingletonTraits<CameraHalDispatcherImpl>;
   // Allow the test to construct the class directly.
@@ -95,6 +100,9 @@ class CAPTURE_EXPORT CameraHalDispatcherImpl final
 
   void StopOnProxyThread();
 
+  void OnTraceLogEnabledOnProxyThread();
+  void OnTraceLogDisabledOnProxyThread();
+
   base::ScopedFD proxy_fd_;
   base::ScopedFD cancel_pipe_;
 

media/capture/video/chromeos/camera_hal_dispatcher_impl_unittest.cc

@@ -34,6 +34,8 @@ class MockCameraHalServer : public cros::mojom::CameraHalServer {
   MOCK_METHOD1(DoCreateChannel,
                void(cros::mojom::CameraModuleRequest& camera_module_request));
 
+  MOCK_METHOD1(SetTracingEnabled, void(bool enabled));
+
   cros::mojom::CameraHalServerPtrInfo GetInterfacePtrInfo() {
     cros::mojom::CameraHalServerPtrInfo camera_hal_server_ptr_info;
     cros::mojom::CameraHalServerRequest camera_hal_server_request =

media/capture/video/chromeos/mojo/cros_camera_service.mojom

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Next min version: 3
+// Next min version: 4
 
 module cros.mojom;
 
@@ -38,13 +38,17 @@ interface CameraHalDispatcher {
 
 // The CrOS camera HAL v3 Mojo server.
 //
-// Next method ID: 1
+// Next method ID: 2
 interface CameraHalServer {
   // A caller calls CreateChannel to create a new Mojo channel to the camera
   // HAL v3 adapter.  Upon successfully binding of |camera_module_request|, the
   // caller will have a established Mojo channel to the camera HAL v3 adapter
   // process.
   CreateChannel@0(CameraModule& camera_module_request);
+
+  // Enable or disable tracing.
+  [MinVersion=3]
+  SetTracingEnabled@1(bool enabled);
 };
 
 // The CrOS camera HAL v3 Mojo client.

media/capture/video/chromeos/stream_buffer_manager.cc

@@ -8,6 +8,7 @@
 #include <memory>
 
 #include "base/posix/safe_strerror.h"
+#include "base/trace_event/trace_event.h"
 #include "media/capture/video/chromeos/camera_buffer_factory.h"
 #include "media/capture/video/chromeos/camera_device_context.h"
 #include "media/capture/video/chromeos/camera_metadata_utils.h"
@@ -579,6 +580,7 @@ void StreamBufferManager::ProcessCaptureResult(
   }
 
   for (const auto& iter : stream_context_) {
+    TRACE_EVENT1("camera", "Capture Result", "frame_number", frame_number);
     SubmitCaptureResultIfComplete(frame_number, iter.first);
   }
 }

media/capture/video/chromeos/video_capture_device_chromeos_halv3.cc

@@ -12,6 +12,7 @@
 #include "base/location.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
+#include "base/trace_event/trace_event.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/capture/video/chromeos/camera_device_context.h"
@@ -61,7 +62,7 @@ void VideoCaptureDeviceChromeOSHalv3::AllocateAndStart(
     std::unique_ptr<Client> client) {
   DCHECK(capture_task_runner_->BelongsToCurrentThread());
   DCHECK(!camera_device_delegate_);
-
+  TRACE_EVENT0("camera", "Start Device");
   if (!camera_device_ipc_thread_.Start()) {
     std::string error_msg = "Failed to start device thread";
     LOG(ERROR) << error_msg;