[sdk] Properly create/remove CPUThrottlingManager instances in tests

R=kimanh@chromium.org

Bug: 490892816
Change-Id: Id134fdb07fa4113fb11b0aa2df92744887527780
Fixed: 491441692
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7653479
Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Auto-Submit: Simon Zünd <szuend@chromium.org>
Commit-Queue: Kim-Anh Tran <kimanh@chromium.org>

Author: szuend

front_end/core/sdk/CPUThrottlingManager.test.ts

@@ -22,15 +22,15 @@ describeWithMockConnection('CPUThrottlingManager', () => {
       return ({getError: () => undefined, result: {value: 42}} as Protocol.Runtime.EvaluateResponse);
     });
 
-    const manager = SDK.CPUThrottlingManager.CPUThrottlingManager.instance();
+    const manager = SDK.CPUThrottlingManager.CPUThrottlingManager.instance({forceNew: true});
     const concurrency = await manager.getHardwareConcurrency();
     assert.strictEqual(concurrency, 42);
   });
 
   it('can set the current hardwareConcurrency', async () => {
     const cdpStub = sinon.stub(target.emulationAgent(), 'invoke_setHardwareConcurrencyOverride').resolves();
 
-    const manager = SDK.CPUThrottlingManager.CPUThrottlingManager.instance();
+    const manager = SDK.CPUThrottlingManager.CPUThrottlingManager.instance({forceNew: true});
     manager.setHardwareConcurrency(5);
 
     sinon.assert.calledOnce(cdpStub);
@@ -40,7 +40,7 @@ describeWithMockConnection('CPUThrottlingManager', () => {
   it('does not set concurrency to 0 or negative numbers', async () => {
     const cdpStub = sinon.stub(target.emulationAgent(), 'invoke_setHardwareConcurrencyOverride').resolves();
 
-    const manager = SDK.CPUThrottlingManager.CPUThrottlingManager.instance();
+    const manager = SDK.CPUThrottlingManager.CPUThrottlingManager.instance({forceNew: true});
     manager.setHardwareConcurrency(0);
     sinon.assert.notCalled(cdpStub);
 

front_end/core/sdk/CPUThrottlingManager.ts

@@ -35,7 +35,7 @@ const str_ = i18n.i18n.registerUIStrings('core/sdk/CPUThrottlingManager.ts', UIS
 const i18nString = i18n.i18n.getLocalizedString.bind(undefined, str_);
 const i18nLazyString = i18n.i18n.getLazilyComputedLocalizedString.bind(undefined, str_);
 
-let throttlingManagerInstance: CPUThrottlingManager;
+let throttlingManagerInstance: CPUThrottlingManager|undefined;
 
 export class CPUThrottlingManager extends Common.ObjectWrapper.ObjectWrapper<EventTypes> implements
     SDKModelObserver<EmulationModel> {
@@ -62,6 +62,10 @@ export class CPUThrottlingManager extends Common.ObjectWrapper.ObjectWrapper<Eve
     return throttlingManagerInstance;
   }
 
+  static removeInstance(): void {
+    throttlingManagerInstance = undefined;
+  }
+
   cpuThrottlingRate(): number {
     return this.#cpuThrottlingOption.rate();
   }

front_end/testing/EnvironmentHelpers.ts

@@ -81,6 +81,7 @@ export async function deinitializeGlobalVars() {
   deinitializeGlobalLocaleVars();
   Logs.NetworkLog.NetworkLog.removeInstance();
   SDK.TargetManager.TargetManager.removeInstance();
+  SDK.CPUThrottlingManager.CPUThrottlingManager.removeInstance();
   SDK.FrameManager.FrameManager.removeInstance();
   Common.Settings.Settings.removeInstance();
   Common.Revealer.RevealerRegistry.removeInstance();