[Devtools] Fixes screencast when devtools is screencasting

third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js

Index: third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js b/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
index e8bba7b930eb6baec8524fde28f3f7d5394bd0f0..a6943525d5810349f1124ea1b691461331d75805 100644
--- a/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
+++ b/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
@@ -127,8 +127,10 @@ Screencast.ScreencastView = class extends UI.VBox {
     }
     dimensions.width *= window.devicePixelRatio;
     dimensions.height *= window.devicePixelRatio;
+    // Note: startScreencast with and height expect to be integers so must be floored.
     this._target.pageAgent().startScreencast(
-        'jpeg', 80, Math.min(maxImageDimension, dimensions.width), Math.min(maxImageDimension, dimensions.height));
+        'jpeg', 80, Math.floor(Math.min(maxImageDimension, dimensions.width)),
+        Math.floor(Math.min(maxImageDimension, dimensions.height)));
     this._target.emulationAgent().setTouchEmulationEnabled(true);
     this._domModel.setHighlighter(this);
   }