Bug 1560207 - Reset all settings on every settings update, to avoid double-constructing. r=jib

Depends on D36192

Differential Revision: https://phabricator.services.mozilla.com/D36193

--HG--
extra : moz-landing-system : lando

dom/media/webrtc/MediaEngineTabVideoSource.cpp

@@ -191,6 +191,7 @@ nsresult MediaEngineTabVideoSource::Reconfigure(
         mBufWidthMax = bufWidthMax;
         mBufHeightMax = bufHeightMax;
         mTimePerFrame = timePerFrame;
+        *mSettings = MediaTrackSettings();
         mSettings->mScrollWithPage.Construct(scrollWithPage);
         mSettings->mWidth.Construct(bufWidthMax);
         mSettings->mHeight.Construct(bufHeightMax);
@@ -198,31 +199,21 @@ nsresult MediaEngineTabVideoSource::Reconfigure(
         if (viewportOffsetX.isSome()) {
           mSettings->mViewportOffsetX.Construct(*viewportOffsetX);
           mViewportOffsetX = *viewportOffsetX;
-        } else {
-          mSettings->mViewportOffsetX.Reset();
         }
         if (viewportOffsetY.isSome()) {
           mSettings->mViewportOffsetY.Construct(*viewportOffsetY);
           mViewportOffsetY = *viewportOffsetY;
-        } else {
-          mSettings->mViewportOffsetY.Reset();
         }
         if (viewportWidth.isSome()) {
           mSettings->mViewportWidth.Construct(*viewportWidth);
           mViewportWidth = *viewportWidth;
-        } else {
-          mSettings->mViewportWidth.Reset();
         }
         if (viewportHeight.isSome()) {
           mSettings->mViewportHeight.Construct(*viewportHeight);
           mViewportHeight = *viewportHeight;
-        } else {
-          mSettings->mViewportHeight.Reset();
         }
         if (windowId != -1) {
           mSettings->mBrowserWindow.Construct(windowId);
-        } else {
-          mSettings->mBrowserWindow.Reset();
         }
       }));
   return NS_OK;