[PTZ] Handle PTZ when processing constraints

This CL makes sure an OverConstrainedError is returned in getUserMedia
if constraints require PTZ and system does not support PTZ.

Bug: 934063
Change-Id: Ia17167bce8eac0d45f4c97d30edbebb032fa55d7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2247820Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/heads/master@{#779974}

third_party/blink/renderer/modules/mediastream/media_stream_constraints_util.cc

@@ -114,14 +114,20 @@ VideoCaptureSettings::VideoCaptureSettings(
     base::Optional<bool> noise_reduction,
     const VideoTrackAdapterSettings& track_adapter_settings,
     base::Optional<double> min_frame_rate,
-    base::Optional<double> max_frame_rate)
+    base::Optional<double> max_frame_rate,
+    base::Optional<double> pan,
+    base::Optional<double> tilt,
+    base::Optional<double> zoom)
     : failed_constraint_name_(nullptr),
       device_id_(std::move(device_id)),
       capture_params_(capture_params),
       noise_reduction_(noise_reduction),
       track_adapter_settings_(track_adapter_settings),
       min_frame_rate_(min_frame_rate),
-      max_frame_rate_(max_frame_rate) {
+      max_frame_rate_(max_frame_rate),
+      pan_(pan),
+      tilt_(tilt),
+      zoom_(zoom) {
   DCHECK(!min_frame_rate ||
          *min_frame_rate_ <= capture_params.requested_format.frame_rate);
   DCHECK(!track_adapter_settings.target_size() ||

third_party/blink/renderer/modules/mediastream/media_stream_constraints_util.h

@@ -69,7 +69,10 @@ class MODULES_EXPORT VideoCaptureSettings {
                        base::Optional<bool> noise_reduction_,
                        const VideoTrackAdapterSettings& track_adapter_settings,
                        base::Optional<double> min_frame_rate,
-                       base::Optional<double> max_frame_rate);
+                       base::Optional<double> max_frame_rate,
+                       base::Optional<double> pan = base::nullopt,
+                       base::Optional<double> tilt = base::nullopt,
+                       base::Optional<double> zoom = base::nullopt);
 
   VideoCaptureSettings(const VideoCaptureSettings& other);
   VideoCaptureSettings& operator=(const VideoCaptureSettings& other);
@@ -127,6 +130,18 @@ class MODULES_EXPORT VideoCaptureSettings {
     DCHECK(HasValue());
     return max_frame_rate_;
   }
+  const base::Optional<double>& pan() const {
+    DCHECK(HasValue());
+    return pan_;
+  }
+  const base::Optional<double>& tilt() const {
+    DCHECK(HasValue());
+    return tilt_;
+  }
+  const base::Optional<double>& zoom() const {
+    DCHECK(HasValue());
+    return zoom_;
+  }
 
  private:
   const char* failed_constraint_name_;
@@ -136,6 +151,9 @@ class MODULES_EXPORT VideoCaptureSettings {
   VideoTrackAdapterSettings track_adapter_settings_;
   base::Optional<double> min_frame_rate_;
   base::Optional<double> max_frame_rate_;
+  base::Optional<double> pan_;
+  base::Optional<double> tilt_;
+  base::Optional<double> zoom_;
 };
 
 // This class represents the output the SelectSettings algorithm for audio