Adopt CharSizeService in MouseHelper

src/TestUtils.test.ts

@@ -14,6 +14,7 @@ import { Terminal } from './Terminal';
 import { AttributeData } from 'core/buffer/BufferLine';
 import { IColorManager, IColorSet } from 'ui/Types';
 import { IOptionsService } from 'common/options/Types';
+import { ICharSizeService } from 'ui/services/Services';
 
 export class TestTerminal extends Terminal {
   writeSync(data: string): void {
@@ -182,15 +183,6 @@ export class MockTerminal implements ITerminal {
   deregisterCharacterJoiner(joinerId: number): void { }
 }
 
-export class MockCharMeasure implements ICharMeasure {
-  onCharSizeChanged: IEvent<void>;
-  width: number;
-  height: number;
-  measure(options: ITerminalOptions): void {
-    throw new Error('Method not implemented.');
-  }
-}
-
 export class MockInputHandlingTerminal implements IInputHandlingTerminal {
   element: HTMLElement;
   options: ITerminalOptions = {};
@@ -438,3 +430,10 @@ export class MockCompositionHelper implements ICompositionHelper {
     return true;
   }
 }
+
+export class MockCharSizeService implements ICharSizeService {
+  get hasValidSize(): boolean { return this.width > 0 && this.height > 0; }
+  onCharSizeChange: IEvent<string>;
+  constructor(public width: number, public height: number) {}
+  measure(): void {}
+}