[sync] Add Sessions integration tests

chrome/browser/sync/test/integration/sync_test.h

Index: chrome/browser/sync/test/integration/sync_test.h
diff --git a/chrome/browser/sync/test/integration/sync_test.h b/chrome/browser/sync/test/integration/sync_test.h
index 818fecd361f33e05cae599675906f49fcea027fd..a66419db33eede300972c2bcdd4b60d471676fab 100644
--- a/chrome/browser/sync/test/integration/sync_test.h
+++ b/chrome/browser/sync/test/integration/sync_test.h
@@ -140,6 +140,13 @@ class SyncTest : public InProcessBrowserTest {
   // and manages its lifetime.
   Browser* GetBrowser(int index) WARN_UNUSED_RESULT;

[skym, 2017/02/24 00:14:09]

Why are all these methods annotated with WARN_UNUSED_RESULT?

[Patrick Noland, 2017/02/24 01:00:40]

Good question, I'll check into that.

[Patrick Noland, 2017/02/27 18:53:26]

I removed them all and it still compiles.

 
+  // Adds a new browser belonging to the profile at |profile_index|, and appends
+  // it to the list of browsers. Creates a copy of the Profile pointer in
+  // position |profile_index| and appends it to the list of profiles. This is
+  // done so that the profile associated with the new browser can be found at

[skym, 2017/02/24 00:14:09]

What does it mean for there to be two Browsers that share a Profile? Is this the
same or different from when I have two windows open for a single profile?

[Patrick Noland, 2017/02/24 01:00:41]

It's having two windows open for the same profile.

+  // the same index as it.
+  Browser* AddBrowser(int profile_index);
+
   // Returns a pointer to a particular sync client. Callee owns the object
   // and manages its lifetime.
   ProfileSyncServiceHarness* GetClient(int index) WARN_UNUSED_RESULT;