Lacros: add logs with info about why lacros-chrome did not launch

Add log warning messages when lacros-chrome didn't launch because:
- The session is not yet active (for instance when using
  "Browse as a Guest")
- The current user is not allowed
- Lacros is not supported or allowed

Bug: None
Change-Id: I06a60daace575a32b46662be36c5ae824a4ea744
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2583622
Commit-Queue: Pilar Molina Lopez <pmolinalopez@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836175}

chrome/browser/chromeos/crosapi/browser_manager.cc

@@ -445,8 +445,12 @@ void BrowserManager::OnSessionStateChanged() {
 
   // Wait for session to become active.
   auto* session_manager = session_manager::SessionManager::Get();
-  if (session_manager->session_state() != session_manager::SessionState::ACTIVE)
+  if (session_manager->session_state() !=
+      session_manager::SessionState::ACTIVE) {
+    LOG(WARNING)
+        << "Session not yet active. Lacros-chrome will not be launched yet";
     return;
+  }
 
   // Ensure this isn't run multiple times.
   session_manager::SessionManager::Get()->RemoveObserver(this);

chrome/browser/chromeos/crosapi/browser_util.cc

@@ -126,23 +126,32 @@ bool IsLacrosEnabled() {
 }
 
 bool IsLacrosEnabled(Channel channel) {
-  if (!base::FeatureList::IsEnabled(chromeos::features::kLacrosSupport))
+  if (!base::FeatureList::IsEnabled(chromeos::features::kLacrosSupport)) {
+    LOG(WARNING) << "Lacros-chrome is not supported";
     return false;
+  }
 
   const User* user = user_manager::UserManager::Get()->GetPrimaryUser();
-  if (!user)
+  if (!user) {
+    LOG(WARNING)
+        << "Unable to get primary user. Lacros-chrome will be disabled";
     return false;
+  }
 
-  if (!IsUserTypeAllowed(user))
+  if (!IsUserTypeAllowed(user)) {
+    LOG(WARNING) << "Current user type not allowed to launch lacros-chrome";
     return false;
+  }
 
   // TODO(https://crbug.com/1135494): Remove the free ticket for
   // Channel::UNKNOWN after the policy is set on server side for developers.
   if (channel == Channel::UNKNOWN)
     return true;
 
-  if (!g_browser_process->local_state()->GetBoolean(prefs::kLacrosAllowed))
+  if (!g_browser_process->local_state()->GetBoolean(prefs::kLacrosAllowed)) {
+    LOG(WARNING) << "Lacros-chrome is not allowed by policy";
     return false;
+  }
 
   switch (channel) {
     case Channel::UNKNOWN: