[PM] Add boundary condition unit tests for V8PerFrameMemoryRequest

Add tests for base::TimeDelta parameters of zero, min, max, and
negative. Fix errors in constructor DCHECK's uncovered by the tests.

Add a gmock InSequence declaration to ExpectBindAndRespondToQuery, which
included two expectations that happened to be in the wrong order. This
makes it usable from inside another InSequence block, and also enforces
the correct order in tests that don't already use InSequence.

R=chrisha

Bug: 1080672
Change-Id: I39ece84cbbeaf23466fd1678bd761f62f54f7d71
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422903
Commit-Queue: Joe Mason <joenotcharles@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Auto-Submit: Joe Mason <joenotcharles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811912}

components/performance_manager/v8_memory/v8_per_frame_memory_decorator.cc

@@ -473,6 +473,7 @@ V8PerFrameMemoryRequest::V8PerFrameMemoryRequest(
     : min_time_between_requests_(min_time_between_requests), mode_(mode) {
 #if DCHECK_IS_ON()
   DCHECK_GT(min_time_between_requests_, base::TimeDelta());
+  DCHECK(!min_time_between_requests_.is_inf());
   DCHECK(mode != MeasurementMode::kEagerForTesting ||
          g_test_eager_measurement_requests_enabled);
 #endif