fix(chips): default click action on chip being prevented

Fixes all the click actions on a chip being prevented. The action wasn't being prevented up until c82aca9 where it got moved out of the `if (this.disabled)`. Since there isn't any info or tests around why it was done this way, I'm assuming that it was by accident.

Fixes #9032.

Author: crisbeto

src/lib/chips/chip.spec.ts

@@ -1,6 +1,6 @@
 import {Directionality} from '@angular/cdk/bidi';
 import {BACKSPACE, DELETE, SPACE} from '@angular/cdk/keycodes';
-import {createKeyboardEvent} from '@angular/cdk/testing';
+import {createKeyboardEvent, dispatchFakeEvent} from '@angular/cdk/testing';
 import {Component, DebugElement} from '@angular/core';
 import {async, ComponentFixture, TestBed} from '@angular/core/testing';
 import {By} from '@angular/platform-browser';
@@ -132,6 +132,24 @@ describe('Chips', () => {
 
         expect(testComponent.chipRemove).toHaveBeenCalledWith({chip: chipInstance});
       });
+
+      it('should not prevent the default click action', () => {
+        const event = dispatchFakeEvent(chipNativeElement, 'click');
+        fixture.detectChanges();
+
+        expect(event.defaultPrevented).toBe(false);
+      });
+
+      it('should prevent the default click action when the chip is disabled', () => {
+        chipInstance.disabled = true;
+        fixture.detectChanges();
+
+        const event = dispatchFakeEvent(chipNativeElement, 'click');
+        fixture.detectChanges();
+
+        expect(event.defaultPrevented).toBe(true);
+      });
+
     });
 
     describe('keyboard behavior', () => {

src/lib/chips/chip.ts

@@ -322,14 +322,12 @@ export class MatChip extends _MatChipMixinBase implements FocusableOption, OnDes
     }
   }
 
-  /** Ensures events fire properly upon click. */
+  /** Handles click events on the chip. */
   _handleClick(event: Event) {
-    // Check disabled
     if (this.disabled) {
-      return;
+      event.preventDefault();
     }
 
-    event.preventDefault();
     event.stopPropagation();
   }