reland of [sync] Add Sessions integration tests

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

Index: chrome/browser/sync/test/integration/sync_test.cc
diff --git a/chrome/browser/sync/test/integration/sync_test.cc b/chrome/browser/sync/test/integration/sync_test.cc
index f40d1f98fd44fbfb4f595c9aa98392743c0720e2..5008beec098bdf7d9f9693c7c3d7ed0ec2a9e1f2 100644
--- a/chrome/browser/sync/test/integration/sync_test.cc
+++ b/chrome/browser/sync/test/integration/sync_test.cc
@@ -419,11 +419,14 @@ Profile* SyncTest::MakeTestProfile(base::FilePath profile_path, int index) {
 }
 
 Profile* SyncTest::GetProfile(int index) {
-  if (profiles_.empty())
-    LOG(FATAL) << "SetupClients() has not yet been called.";
-  if (index < 0 || index >= static_cast<int>(profiles_.size()))
-    LOG(FATAL) << "GetProfile(): Index is out of bounds.";
-  return profiles_[index];
+  EXPECT_FALSE(profiles_.empty()) << "SetupClients() has not yet been called.";
+  EXPECT_FALSE(index < 0 || index >= static_cast<int>(profiles_.size()))
+      << "GetProfile(): Index is out of bounds.";
+
+  Profile* profile = profiles_[index];
+  EXPECT_NE(nullptr, profile) << "No profile found at index: " << index;
+
+  return profile;
 }
 
 std::vector<Profile*> SyncTest::GetAllProfiles() {
@@ -438,13 +441,24 @@ std::vector<Profile*> SyncTest::GetAllProfiles() {
 }
 
 Browser* SyncTest::GetBrowser(int index) {
-  if (browsers_.empty())
-    LOG(FATAL) << "SetupClients() has not yet been called.";
-  if (index < 0 || index >= static_cast<int>(browsers_.size()))
-    LOG(FATAL) << "GetBrowser(): Index is out of bounds.";
+  EXPECT_FALSE(browsers_.empty()) << "SetupClients() has not yet been called.";
+  EXPECT_FALSE(index < 0 || index >= static_cast<int>(browsers_.size()))
+      << "GetBrowser(): Index is out of bounds.";
+
+  Browser* browser = browsers_[index];
+  EXPECT_NE(browser, nullptr);
+
   return browsers_[index];
 }
 
+Browser* SyncTest::AddBrowser(int profile_index) {
+  Profile* profile = GetProfile(profile_index);
+  browsers_.push_back(new Browser(Browser::CreateParams(profile, true)));
+  profiles_.push_back(profile);
+
+  return browsers_[browsers_.size() - 1];
+}
+
 ProfileSyncServiceHarness* SyncTest::GetClient(int index) {
   if (clients_.empty())
     LOG(FATAL) << "SetupClients() has not yet been called.";
@@ -487,7 +501,6 @@ bool SyncTest::SetupClients() {
   profiles_.resize(num_clients_);
   profile_delegates_.resize(num_clients_ + 1);  // + 1 for the verifier.
   tmp_profile_paths_.resize(num_clients_);
-  browsers_.resize(num_clients_);
   clients_.resize(num_clients_);
   invalidation_forwarders_.resize(num_clients_);
   sync_refreshers_.resize(num_clients_);
@@ -528,11 +541,7 @@ void SyncTest::InitializeProfile(int index, Profile* profile) {
   DCHECK(profile);
   profiles_[index] = profile;
 
-  // CheckInitialState() assumes that no windows are open at startup.
-  browsers_[index] =
-      new Browser(Browser::CreateParams(GetProfile(index), true));
-
-  EXPECT_NE(nullptr, GetBrowser(index)) << "Could not create Browser " << index;
+  AddBrowser(index);
 
   // Make sure the ProfileSyncService has been created before creating the
   // ProfileSyncServiceHarness - some tests expect the ProfileSyncService to