blinky: Simplify test time advancement

AdvanceUntilNextExpiration() rather than AdvanceTime(some_interval)
avoids the need to fruitlessly loop over time periods during which
nothing happens. This also avoids the need to specify an arbitrary
interval with which to advance time.

Change-Id: Idba8beadf70bcb849f871412f5d95fd928113ce7
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/235752
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Taylor Cramer <cramertj@google.com>
Reviewed-by: Aaron Green <aarongreen@google.com>
diff --git a/modules/blinky/blinky_test.cc b/modules/blinky/blinky_test.cc
index 8a2c554..e7de798 100644
--- a/modules/blinky/blinky_test.cc
+++ b/modules/blinky/blinky_test.cc
@@ -107,7 +107,7 @@
   EXPECT_EQ(blinky_.Blink(1, kIntervalMs), pw::OkStatus());
   while (!blinky_.IsIdle()) {
     dispatcher_.RunUntilStalled().IgnorePoll();
-    time_.AdvanceTime(kInterval);
+    time_.AdvanceUntilNextExpiration();
   }
 
   auto event = FirstActive();
@@ -126,7 +126,7 @@
   EXPECT_EQ(blinky_.Blink(100, kIntervalMs), pw::OkStatus());
   while (!blinky_.IsIdle()) {
     dispatcher_.RunUntilStalled().IgnorePoll();
-    time_.AdvanceTime(kInterval);
+    time_.AdvanceUntilNextExpiration();
   }
 
   // Every "on" and "off" is recorded.
@@ -139,7 +139,7 @@
   EXPECT_EQ(blinky_.Blink(1, kIntervalMs * 32), pw::OkStatus());
   while (!blinky_.IsIdle()) {
     dispatcher_.RunUntilStalled().IgnorePoll();
-    time_.AdvanceTime(kInterval);
+    time_.AdvanceUntilNextExpiration();
   }
 
   auto event = FirstActive();