Eliminate reloadForCleanStateIfNeeded

lighthouse-core/gather/drivers/driver.js

@@ -340,22 +340,6 @@ class Driver {
       .then(_ => waitForLoad && this._waitForFullyLoaded(pauseAfterLoadMs));
   }
 
-  /**
-   * @param {!Object} options
-   * @return {!Promise}
-   */
-  reloadForCleanStateIfNeeded(options) {
-    if (!options.restoreCleanState) {
-      return Promise.resolve();
-    }
-
-    const status = 'Reloading page to reset state';
-    log.log('status', status);
-    return this.gotoURL(options.url).then(_ => {
-      log.log('statusEnd', status);
-    });
-  }
-
   /**
    * @param {string} selector Selector to find in the DOM
    * @return {!Promise<Element>} The found element, or null, resolved in a promise

lighthouse-core/gather/drivers/extension.js

@@ -90,6 +90,8 @@ class ExtensionConnection extends Connection {
         if (chrome.runtime.lastError) {
           return reject(chrome.runtime.lastError);
         }
+        // Reload the target page to restore its state.
+        chrome.tabs.reload(tabId);
         resolve();
       });
     }).then(_ => this._detachCleanup());

lighthouse-core/gather/gather-runner.js

@@ -45,9 +45,8 @@ const path = require('path');
  *     ii. all gatherer's afterPass()
  *
  * 3. Teardown
- *   A. reloadForCleanStateIfNeeded
- *   B. driver.disconnect()
- *   C. collect all artifacts and return them
+ *   A. driver.disconnect()
+ *   B. collect all artifacts and return them
  */
 class GatherRunner {
   /**
@@ -243,14 +242,9 @@ class GatherRunner {
         });
       })
       .then(_ => {
-        // We dont need to hold up the reporting for the reload/disconnect,
-        // so we will not return a promise in here.
-        driver.reloadForCleanStateIfNeeded(options).then(_ => {
-          log.log('status', 'Disconnecting from browser...');
-          driver.disconnect();
-        });
-      })
-      .then(_ => {
+        log.log('status', 'Disconnecting from browser...');
+        return driver.disconnect();
+      }).then(_ => {
         // Collate all the gatherer results.
         const computedArtifacts = this.instantiateComputedArtifacts();
         const artifacts = Object.assign({}, computedArtifacts, tracingData);

lighthouse-core/test/gather/fake-driver.js

@@ -34,9 +34,6 @@ module.exports = {
   },
   cleanAndDisableBrowserCaches() {},
   clearDataForOrigin() {},
-  reloadForCleanStateIfNeeded() {
-    return Promise.resolve();
-  },
   beginTrace() {
     return Promise.resolve();
   },