Remove scroll refresh on _getDimension

This was causing layouts to happen on resize an it's unnecessary as it's
being run on setVisible too.

src/vs/workbench/parts/terminal/electron-browser/terminalInstance.ts

@@ -243,15 +243,6 @@ export class TerminalInstance implements ITerminalInstance {
 		// The panel is minimized
 		if (!height) {
 			return TerminalInstance._lastKnownDimensions;
-		} else {
-			// Trigger scroll event manually so that the viewport's scroll area is synced. This
-			// needs to happen otherwise its scrollTop value is invalid when the panel is toggled as
-			// it gets removed and then added back to the DOM (resetting scrollTop to 0).
-			// Upstream issue: https://github.com/sourcelair/xterm.js/issues/291
-			if (this._xterm) {
-				// TODO: See if we can live without this now
-				this._xterm.emit('scroll', this._xterm.buffer.ydisp);
-			}
 		}
 
 		if (!this._wrapperElement) {