Make time_to_first_suspension's default 1800sec

chrome/browser/memory/tab_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_MEMORY_TAB_MANAGER_H_
 #define CHROME_BROWSER_MEMORY_TAB_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 160 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, InvalidOrEmptyURL);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, IsInternalPage);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, OomPressureListener);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ProtectPDFPages);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ProtectRecentlyUsedTabs);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ProtectVideoTabs);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ReloadDiscardedTabContextMenu);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, TabManagerBasics);
   FRIEND_TEST_ALL_PREFIXES(TabManagerWebContentsDataTest, PurgeAndSuspendState);
 
+  // The time of the first purging after a renderer is backgrounded.
+  // There is no strong reason why its default value is 30 minutes.

[Wez, 2017/02/17 19:03:14]

nit: No need to say "no strong reason"; sufficient to say "this initial value
was chosen to <reason>", for example.

[tasak, 2017/02/20 07:07:15]

Done.

+  // At least, the value should not be small, because quickly purging memory
+  // makes it slower to switch tabs.
+  static const int kDefaultTimeToFirstSuspensionSeconds = 1800;

[Wez, 2017/02/17 19:03:14]

Note that you'll also need to fix this in the Finch configuration.

[Wez, 2017/02/17 19:03:14]

nit: I'd suggest using "Suspend" rather than "Suspension" here, so that it's
easy for someone doing a dumb search through the code for "Suspend" to find the
constant.  However, I'd also recommend naming it according to what it actually
does, so kDefaultTimeToFirstPurgeInSeconds, for example.

[tasak, 2017/02/20 07:07:15]

Done.

[tasak, 2017/02/20 07:07:15]

Acknowledged.

+
   // This is needed so WebContentsData can call OnDiscardedStateChange, and
   // can use PurgeAndSuspendState.
   friend class WebContentsData;
 
   // Called by WebContentsData whenever the discard state of a WebContents
   // changes, so that observers can be informed.
   void OnDiscardedStateChange(content::WebContents* contents,
                               bool is_discarded);
 
   // Called by WebContentsData whenever the auto-discardable state of a
@@ skipping 229 matching lines @@
 
   // Weak pointer factory used for posting delayed tasks to task_runner_.
   base::WeakPtrFactory<TabManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TabManager);
 };
 
 }  // namespace memory
 
 #endif  // CHROME_BROWSER_MEMORY_TAB_MANAGER_H_