🤠 Make BackForwardCacheBrowserTest.VideoSuspendAndResume less flaky.

The test was failing with the following error:
```
../../content/browser/back_forward_cache_browsertest.cc:5429: Failure
Expected: (0.01) > (duration2 - duration1), actual: 0.01 vs 0.011018
```

TBR=altimin@chromium.org,hajimehoshi@chromium.org

BUG=1127833

Fixed: 1127833
Change-Id: Ic0a5c531ab1b9aaa6e9ddac0b009b9add5c72966
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2409898Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Hajime Hoshi <hajimehoshi@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806607}

content/browser/back_forward_cache_browsertest.cc

@@ -5426,7 +5426,7 @@ IN_PROC_BROWSER_TEST_F(BackForwardCacheBrowserTest, VideoSuspendAndResume) {
   double duration1 = EvalJs(rfh_a, "timeOnFrozen;").ExtractDouble();
   double duration2 = EvalJs(rfh_a, "video.currentTime;").ExtractDouble();
   EXPECT_LE(0.0, duration2 - duration1);
-  EXPECT_GT(0.01, duration2 - duration1);
+  EXPECT_GT(0.02, duration2 - duration1);
 
   // Resume the media.
   EXPECT_TRUE(ExecJs(rfh_a, "video.play();"));