Add a flag to use fake camera for getUserMedia()

Add a flag --use-fake-device-for-media-stream for replacing actual
camera with a fake one.

The fake camera also generates a visual beep every 1 second.

BUG=


Review URL: https://chromiumcodereview.appspot.com/11270026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@164313 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 18 insertions, 2 deletions

diff --git a/media/video/capture/fake_video_capture_device.cc b/media/video/capture/fake_video_capture_device.cc
index 7512060..77afe8e 100644
--- a/media/video/capture/fake_video_capture_device.cc
+++ b/media/video/capture/fake_video_capture_device.cc
@@ -12,7 +12,8 @@
 
 namespace media {
 
-static const int kFakeCaptureTimeoutMs = 100;
+static const int kFakeCaptureTimeoutMs = 50;
+static const int kFakeCaptureBeepCycle = 20;  // Visual beep every 1s.
 enum { kNumberOfFakeDevices = 2 };
 
 bool FakeVideoCaptureDevice::fail_next_create_ = false;
@@ -52,7 +53,8 @@ FakeVideoCaptureDevice::FakeVideoCaptureDevice(const Name& device_name)
       observer_(NULL),
       state_(kIdle),
       capture_thread_("CaptureThread"),
-      frame_size_(0) {
+      frame_size_(0),
+      frame_count_(0) {
 }
 
 FakeVideoCaptureDevice::~FakeVideoCaptureDevice() {
@@ -130,6 +132,15 @@ void FakeVideoCaptureDevice::OnCaptureTask() {
   if (state_ != kCapturing) {
     return;
   }
+
+  bool beep = false;
+  if (frame_count_ % kFakeCaptureBeepCycle == 0) {
+    beep = true;
+    // This will fill the frame in grey.
+    memset(fake_frame_.get(), 128, frame_size_);
+  }
+  frame_count_++;
+
   // Give the captured frame to the observer.
   observer_->OnIncomingCapturedFrame(fake_frame_.get(),
                                      frame_size_,
@@ -140,6 +151,10 @@ void FakeVideoCaptureDevice::OnCaptureTask() {
         base::Bind(&FakeVideoCaptureDevice::OnCaptureTask,
                    base::Unretained(this)),
         base::TimeDelta::FromMilliseconds(kFakeCaptureTimeoutMs));
+
+  if (beep) {
+    memset(fake_frame_.get(), 0, frame_size_);
+  }
 }
 
 }  // namespace media
diff --git a/media/video/capture/fake_video_capture_device.h b/media/video/capture/fake_video_capture_device.h
index bbb7569..082bc0e 100644
--- a/media/video/capture/fake_video_capture_device.h
+++ b/media/video/capture/fake_video_capture_device.h
@@ -55,6 +55,7 @@ class MEDIA_EXPORT FakeVideoCaptureDevice : public VideoCaptureDevice {
   base::Thread capture_thread_;
   int frame_size_;
   scoped_array<uint8> fake_frame_;
+  int frame_count_;
 
   static bool fail_next_create_;