perf(material/icon): remove IE workaround (angular#24514)

Removes an IE-specific workaround that had some minor performance implications.

Author: crisbeto

src/material/icon/icon.spec.ts

@@ -877,29 +877,6 @@ describe('MatIcon', () => {
       expect(svgElement.getAttribute('viewBox')).toBe('0 0 43 43');
     });
 
-    it('should add an extra string to the end of `style` tags inside SVG', fakeAsync(() => {
-      iconRegistry.addSvgIconLiteral(
-        'fido',
-        trustHtml(`
-        <svg>
-          <style>#woof {color: blue;}</style>
-          <path id="woof" name="woof"></path>
-        </svg>
-      `),
-      );
-
-      const fixture = TestBed.createComponent(IconFromSvgName);
-      fixture.componentInstance.iconName = 'fido';
-      fixture.detectChanges();
-      const styleTag = fixture.nativeElement.querySelector('mat-icon svg style');
-
-      // Note the extra whitespace at the end which is what we're testing for. This is a
-      // workaround for IE and Edge ignoring `style` tags in dynamically-created SVGs.
-      expect(styleTag.textContent).toBe('#woof {color: blue;} ');
-
-      tick();
-    }));
-
     it('should prepend the current path to attributes with `url()` references', fakeAsync(() => {
       iconRegistry.addSvgIconLiteral(
         'fido',

src/material/icon/icon.ts

@@ -321,15 +321,6 @@ export class MatIcon extends _MatIconBase implements OnInit, AfterViewChecked, C
   private _setSvgElement(svg: SVGElement) {
     this._clearSvgElement();
 
-    // Workaround for IE11 and Edge ignoring `style` tags inside dynamically-created SVGs.
-    // See: https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10898469/
-    // Do this before inserting the element into the DOM, in order to avoid a style recalculation.
-    const styleTags = svg.querySelectorAll('style') as NodeListOf<HTMLStyleElement>;
-
-    for (let i = 0; i < styleTags.length; i++) {
-      styleTags[i].textContent += ' ';
-    }
-
     // Note: we do this fix here, rather than the icon registry, because the
     // references have to point to the URL at the time that the icon was created.
     const path = this._location.getPathname();