Remove TabManager::(Discard|Freeze)TabById().

These methods were only used by the chrome://discards UI, which can
instead access the LifecycleUnits directly.

Bug: 775644
Change-Id: Iae97a1d6bcf5af1fcd555608ad05e4921ff8e437
Reviewed-on: https://chromium-review.googlesource.com/1057692
Commit-Queue: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Fadi Meawad <fmeawad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558759}

chrome/browser/resource_coordinator/tab_manager.cc

@@ -284,24 +284,6 @@ void TabManager::DiscardTab(DiscardReason reason) {
   DiscardTabImpl(reason);
 }
 
-void TabManager::DiscardTabById(int32_t tab_id, DiscardReason reason) {
-  for (LifecycleUnit* lifecycle_unit : lifecycle_units_) {
-    if (lifecycle_unit->GetID() == tab_id) {
-      lifecycle_unit->Discard(reason);
-      return;
-    }
-  }
-}
-
-void TabManager::FreezeTabById(int32_t tab_id) {
-  for (LifecycleUnit* lifecycle_unit : lifecycle_units_) {
-    if (lifecycle_unit->GetID() == tab_id) {
-      lifecycle_unit->Freeze();
-      return;
-    }
-  }
-}
-
 WebContents* TabManager::DiscardTabByExtension(content::WebContents* contents) {
   if (contents) {
     TabLifecycleUnitExternal* tab_lifecycle_unit_external =

chrome/browser/resource_coordinator/tab_manager.h

@@ -107,17 +107,6 @@ class TabManager : public LifecycleUnitObserver,
   // unload handler and fast-kill the tab regardless).
   void DiscardTab(DiscardReason reason);
 
-  // Discards a tab with the given unique ID. The tab still exists in the
-  // tab-strip; clicking on it will reload it. Returns null if the tab cannot
-  // be found or cannot be discarded. Otherwise returns the new web_contents
-  // of the discarded tab.
-  void DiscardTabById(int32_t tab_id, DiscardReason reason);
-
-  // Freezes a tab with the given unique ID. Unlike discarding, freezing does
-  // not kill or change the tab other than stopping its task queues. Revisiting
-  // the tab causes it to unfreeze.
-  void FreezeTabById(int32_t tab_id);
-
   // Method used by the extensions API to discard tabs. If |contents| is null,
   // discards the least important tab using DiscardTab(). Otherwise discards
   // the given contents. Returns the new web_contents or null if no tab

chrome/browser/ui/webui/discards/discards_ui.cc

@@ -50,6 +50,15 @@ mojom::LifecycleUnitVisibility GetLifecycleUnitVisibility(
 #endif
 }
 
+resource_coordinator::LifecycleUnit* GetLifecycleUnitById(int32_t id) {
+  for (resource_coordinator::LifecycleUnit* lifecycle_unit :
+       g_browser_process->GetTabManager()->GetSortedLifecycleUnits()) {
+    if (lifecycle_unit->GetID() == id)
+      return lifecycle_unit;
+  }
+  return nullptr;
+}
+
 class DiscardsDetailsProviderImpl : public mojom::DiscardsDetailsProvider {
  public:
   // This instance is deleted when the supplied pipe is destroyed.
@@ -108,28 +117,32 @@ class DiscardsDetailsProviderImpl : public mojom::DiscardsDetailsProvider {
     std::move(callback).Run(std::move(infos));
   }
 
-  void SetAutoDiscardable(int32_t tab_id,
+  void SetAutoDiscardable(int32_t id,
                           bool is_auto_discardable,
                           SetAutoDiscardableCallback callback) override {
-    resource_coordinator::TabManager* tab_manager =
-        g_browser_process->GetTabManager();
-    tab_manager->SetTabAutoDiscardableState(tab_id, is_auto_discardable);
+    auto* lifecycle_unit = GetLifecycleUnitById(id);
+    if (lifecycle_unit) {
+      auto* tab_lifecycle_unit_external =
+          lifecycle_unit->AsTabLifecycleUnitExternal();
+      if (tab_lifecycle_unit_external)
+        tab_lifecycle_unit_external->SetAutoDiscardable(is_auto_discardable);
+    }
     std::move(callback).Run();
   }
 
-  void DiscardById(int32_t tab_id,
+  void DiscardById(int32_t id,
                    bool urgent,
                    DiscardByIdCallback callback) override {
-    resource_coordinator::TabManager* tab_manager =
-        g_browser_process->GetTabManager();
-    tab_manager->DiscardTabById(tab_id, GetDiscardReason(urgent));
+    auto* lifecycle_unit = GetLifecycleUnitById(id);
+    if (lifecycle_unit)
+      lifecycle_unit->Discard(GetDiscardReason(urgent));
     std::move(callback).Run();
   }
 
-  void FreezeById(int32_t tab_id) override {
-    resource_coordinator::TabManager* tab_manager =
-        g_browser_process->GetTabManager();
-    tab_manager->FreezeTabById(tab_id);
+  void FreezeById(int32_t id) override {
+    auto* lifecycle_unit = GetLifecycleUnitById(id);
+    if (lifecycle_unit)
+      lifecycle_unit->Freeze();
   }
 
   void Discard(bool urgent, DiscardCallback callback) override {