Re-enable synthetic memory signal for pagecycler tests.

This was commented out last week to unlock the automerger
due to some changes upstream, which have been resynced.

Change-Id: Iccaaae5ceff11b0cbf90c30d1a2aa3b325197716
diff --git a/chromium/java/com/android/webview/chromium/WebViewChromiumFactoryProvider.java b/chromium/java/com/android/webview/chromium/WebViewChromiumFactoryProvider.java
index abc75f7..6245ebf 100644
--- a/chromium/java/com/android/webview/chromium/WebViewChromiumFactoryProvider.java
+++ b/chromium/java/com/android/webview/chromium/WebViewChromiumFactoryProvider.java
@@ -210,11 +210,10 @@
 
                     @Override
                     public void freeMemoryForTests() {
-                        // TODO(primiano): temporarily commented out to unlock the automerger.
-                        // if (ActivityManager.isRunningInTestHarness()) {
-                        //     MemoryPressureListener.simulateMemoryPressureSignal(
-                        //             ComponentCallbacks2.TRIM_MEMORY_COMPLETE);
-                        // }
+                        if (ActivityManager.isRunningInTestHarness()) {
+                            MemoryPressureListener.maybeNotifyMemoryPresure(
+                                    ComponentCallbacks2.TRIM_MEMORY_COMPLETE);
+                        }
                     }
                 };
             }