src/vs/workbench/browser/parts/views/viewPaneContainer.ts/ViewPaneContainer/restoreViewSizes
class ViewPaneContainer:	private restoreViewSizes(): void {
		// Restore sizes only when the layout has happened
		if (this.didLayout) {
			let initialSizes;
			for (let i = 0; i < this.viewContainerModel.visibleViewDescriptors.length; i++) {
				const pane = this.panes[i];
				const viewDescriptor = this.viewContainerModel.visibleViewDescriptors[i];
				const size = this.viewContainerModel.getSize(viewDescriptor.id);

				if (typeof size === 'number') {
					this.resizePane(pane, size);
				} else {
					initialSizes = initialSizes ? initialSizes : this.computeInitialSizes();
					this.resizePane(pane, initialSizes.get(pane.id) || 200);
				}
			}
		}
	}