[TabManager] Start function refactoring.

chrome/browser/memory/tab_manager.cc

Index: chrome/browser/memory/tab_manager.cc
diff --git a/chrome/browser/memory/tab_manager.cc b/chrome/browser/memory/tab_manager.cc
index f89f8e485d3ec9b492c5bac5f113e00e77bf5392..1c5561b631eb95273d7b5bcb1156e96da1965799 100644
--- a/chrome/browser/memory/tab_manager.cc
+++ b/chrome/browser/memory/tab_manager.cc
@@ -165,15 +165,6 @@ void TabManager::Start() {
   if (!base::FeatureList::IsEnabled(features::kAutomaticTabDiscarding))
     return;
 
-  // Check the variation parameter to see if a tab be discarded more than once.
-  // Default is to only discard once per tab.
-  std::string allow_multiple_discards = variations::GetVariationParamValue(
-      features::kAutomaticTabDiscarding.name, "AllowMultipleDiscards");
-  if (allow_multiple_discards == "true")
-    discard_once_ = true;
-  else
-    discard_once_ = false;
-
   // Check the variation parameter to see if a tab is to be protected for an
   // amount of time after being backgrounded. The value is in seconds.
   std::string minimum_protection_time_string =
@@ -188,13 +179,11 @@ void TabManager::Start() {
             base::TimeDelta::FromSeconds(minimum_protection_time_seconds);
     }
   }
-
-#elif defined(OS_CHROMEOS)
-  // On Chrome OS, tab manager is always started and tabs can be discarded more
-  // than once.
-  discard_once_ = false;
 #endif
 
+  // Check if multiple discards are allowed.
+  discard_once_ = !AllowMultipleDiscards();
+
   if (!update_timer_.IsRunning()) {
     update_timer_.Start(FROM_HERE,
                         TimeDelta::FromSeconds(kAdjustmentIntervalSeconds),
@@ -561,8 +550,8 @@ void TabManager::PurgeAndSuspendBackgroundedTabs() {
   }
   if (purge_and_suspend_time <= 0)
     return;
-  auto purge_and_suspend_time_threshold = NowTicks() -
-      base::TimeDelta::FromSeconds(purge_and_suspend_time);
+  auto purge_and_suspend_time_threshold =
+      NowTicks() - base::TimeDelta::FromSeconds(purge_and_suspend_time);
   auto tab_stats = GetUnsortedTabStats();
   for (auto& tab : tab_stats) {
     if (!tab.render_process_host->IsProcessBackgrounded())
@@ -858,6 +847,20 @@ bool TabManager::DiscardTabImpl() {
   return false;
 }
 
+// Check the variation parameter to see if a tab be discarded more than once.
+// Default is to only discard once per tab.
+bool TabManager::AllowMultipleDiscards() {

[Georges Khalil, 2016/05/17 13:49:07]

Rename this to ShouldOnlyDiscardOnce and flip logic.

[Anderson Silva, 2016/05/17 15:12:02]

Acknowledged.

+#if defined(OS_CHROMEOS)
+  // On Chrome OS, tab manager is always started and tabs can be discarded more
+  // than once.
+  return true;
+#endif
+
+  std::string allow_multiple_discards = variations::GetVariationParamValue(
+      features::kAutomaticTabDiscarding.name, "AllowMultipleDiscards");
+  return (allow_multiple_discards == "true");
+}
+
 // Things to collect on the browser thread (because TabStripModel isn't thread
 // safe):
 // 1) whether or not a tab is pinned