Order TabManager functions.

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 296947636c5982a7aeaf5ebff72212798dda0123..a99e6abdc048bd79f91e73bd4fe68c6b523fc5f1 100644
--- a/chrome/browser/memory/tab_manager.cc
+++ b/chrome/browser/memory/tab_manager.cc
@@ -271,6 +271,62 @@ bool TabManager::IsTabDiscarded(content::WebContents* contents) const {
   return GetWebContentsData(contents)->IsDiscarded();
 }
 
+bool TabManager::CanDiscardTab(int64_t target_web_contents_id) const {
+  TabStripModel* model;
+  int idx = FindTabStripModelById(target_web_contents_id, &model);
+
+  if (idx == -1)
+    return false;
+
+  WebContents* web_contents = model->GetWebContentsAt(idx);
+
+  // Do not discard tabs that don't have a valid URL (most probably they have
+  // just been opened and dicarding them would lose the URL).
+  // TODO(georgesak): Look into a workaround to be able to kill the tab without
+  // losing the pending navigation.
+  if (!web_contents->GetLastCommittedURL().is_valid() ||
+      web_contents->GetLastCommittedURL().is_empty()) {
+    return false;
+  }
+
+  // Do not discard tabs in which the user has entered text in a form, lest that
+  // state gets lost.
+  if (web_contents->GetPageImportanceSignals().had_form_interaction)
+    return false;
+
+  // Do not discard tabs that are playing either playing audio or accessing the
+  // microphone or camera as it's too distruptive to the user experience. Note
+  // that tabs that have recently stopped playing audio by at least
+  // |kAudioProtectionTimeSeconds| seconds are protected as well.
+  if (IsMediaTab(web_contents))
+    return false;
+
+  // Do not discard PDFs as they might contain entry that is not saved and they
+  // don't remember their scrolling positions. See crbug.com/547286 and
+  // crbug.com/65244.
+  // TODO(georgesak): Remove this workaround when the bugs are fixed.
+  if (web_contents->GetContentsMimeType() == "application/pdf")
+    return false;
+
+  // Do not discard a previously discarded tab if that's the desired behavior.
+  if (discard_once_ && GetWebContentsData(web_contents)->DiscardCount() > 0)
+    return false;
+
+  // Do not discard a recently used tab.
+  if (minimum_protection_time_.InSeconds() > 0) {
+    auto delta =
+        NowTicks() - GetWebContentsData(web_contents)->LastInactiveTime();
+    if (delta < minimum_protection_time_)
+      return false;
+  }
+
+  // Do not discard a tab that was explicitly disallowed to.
+  if (!IsTabAutoDiscardable(web_contents))
+    return false;
+
+  return true;
+}
+
 void TabManager::DiscardTab() {
 #if defined(OS_CHROMEOS)
   // Call Chrome OS specific low memory handling process.
@@ -316,47 +372,115 @@ void TabManager::set_test_tick_clock(base::TickClock* test_tick_clock) {
   test_tick_clock_ = test_tick_clock;
 }
 
-void TabManager::TabChangedAt(content::WebContents* contents,
-                              int index,
-                              TabChangeType change_type) {
-  if (change_type != TabChangeType::ALL)
-    return;
-  auto* data = GetWebContentsData(contents);
-  bool old_state = data->IsRecentlyAudible();
-  bool current_state = contents->WasRecentlyAudible();
-  if (old_state != current_state) {
-    data->SetRecentlyAudible(current_state);
-    data->SetLastAudioChangeTime(NowTicks());
+// Things to collect on the browser thread (because TabStripModel isn't thread
+// safe):
+// 1) whether or not a tab is pinned
+// 2) last time a tab was selected
+// 3) is the tab currently selected
+TabStatsList TabManager::GetUnsortedTabStats() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  TabStatsList stats_list;
+  stats_list.reserve(32);  // 99% of users have < 30 tabs open.
+
+  // TODO(chrisha): Move this code to a TabStripModel enumeration delegate!
+  if (!test_tab_strip_models_.empty()) {
+    for (size_t i = 0; i < test_tab_strip_models_.size(); ++i) {
+      AddTabStats(test_tab_strip_models_[i].first,   // tab_strip_model
+                  test_tab_strip_models_[i].second,  // is_app
+                  i == 0,                            // is_active
+                  &stats_list);
+    }
+  } else {
+    // The code here can only be tested under a full browser test.
+    AddTabStats(&stats_list);
   }
+
+  return stats_list;
 }
 
-void TabManager::ActiveTabChanged(content::WebContents* old_contents,
-                                  content::WebContents* new_contents,
-                                  int index,
-                                  int reason) {
-  GetWebContentsData(new_contents)->SetDiscardState(false);
-  // If |old_contents| is set, that tab has switched from being active to
-  // inactive, so record the time of that transition.
-  if (old_contents)
-    GetWebContentsData(old_contents)->SetLastInactiveTime(NowTicks());
+void TabManager::AddObserver(TabManagerObserver* observer) {
+  observers_.AddObserver(observer);
 }
 
-void TabManager::TabInsertedAt(content::WebContents* contents,
-                               int index,
-                               bool foreground) {
-  // Only interested in background tabs, as foreground tabs get taken care of by
-  // ActiveTabChanged.
-  if (foreground)
-    return;
+void TabManager::RemoveObserver(TabManagerObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
 
-  // A new background tab is similar to having a tab switch from being active to
-  // inactive.
-  GetWebContentsData(contents)->SetLastInactiveTime(NowTicks());
+void TabManager::set_minimum_protection_time_for_tests(
+    base::TimeDelta minimum_protection_time) {
+  minimum_protection_time_ = minimum_protection_time;
+}
+
+bool TabManager::IsTabAutoDiscardable(content::WebContents* contents) const {
+  return GetWebContentsData(contents)->IsAutoDiscardable();
+}
+
+void TabManager::SetTabAutoDiscardableState(content::WebContents* contents,
+                                            bool state) {
+  GetWebContentsData(contents)->SetAutoDiscardableState(state);
+}
+
+// static
+bool TabManager::CompareTabStats(const TabStats& first,
+                                 const TabStats& second) {
+  // Being currently selected is most important to protect.
+  if (first.is_selected != second.is_selected)
+    return first.is_selected;
+
+  // Non auto-discardable tabs are more important to protect.
+  if (first.is_auto_discardable != second.is_auto_discardable)
+    return !first.is_auto_discardable;
+
+  // Protect tabs with pending form entries.
+  if (first.has_form_entry != second.has_form_entry)
+    return first.has_form_entry;
+
+  // Protect streaming audio and video conferencing tabs as these are similar to
+  // active tabs.
+  if (first.is_media != second.is_media)
+    return first.is_media;
+
+  // Tab with internal web UI like NTP or Settings are good choices to discard,
+  // so protect non-Web UI and let the other conditionals finish the sort.
+  if (first.is_internal_page != second.is_internal_page)
+    return !first.is_internal_page;
+
+  // Being pinned is important to protect.
+  if (first.is_pinned != second.is_pinned)
+    return first.is_pinned;
+
+  // Being an app is important too, as it's the only visible surface in the
+  // window and should not be discarded.
+  if (first.is_app != second.is_app)
+    return first.is_app;
+
+  // TODO(jamescook): Incorporate sudden_termination_allowed into the sort
+  // order. This is currently not done because pages with unload handlers set
+  // sudden_termination_allowed false, and that covers too many common pages
+  // with ad networks and statistics scripts.  Ideally check for beforeUnload
+  // handlers, which are likely to present a dialog asking if the user wants to
+  // discard state.  crbug.com/123049.
+
+  // Being more recently active is more important.
+  return first.last_active > second.last_active;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // TabManager, private:
 
+void TabManager::OnDiscardedStateChange(content::WebContents* contents,
+                                        bool is_discarded) {
+  FOR_EACH_OBSERVER(TabManagerObserver, observers_,
+                    OnDiscardedStateChange(contents, is_discarded));
+}
+
+void TabManager::OnAutoDiscardableStateChange(content::WebContents* contents,
+                                              bool is_auto_discardable) {
+  FOR_EACH_OBSERVER(
+      TabManagerObserver, observers_,
+      OnAutoDiscardableStateChange(contents, is_auto_discardable));
+}
+
 // static
 void TabManager::PurgeMemoryAndDiscardTab() {
   if (g_browser_process && g_browser_process->GetTabManager()) {
@@ -488,8 +612,7 @@ void TabManager::AddTabStats(const TabStripModel* model,
     if (!contents->IsCrashed()) {
       TabStats stats;
       stats.is_app = is_app;
-      stats.is_internal_page =
-          IsInternalPage(contents->GetLastCommittedURL());
+      stats.is_internal_page = IsInternalPage(contents->GetLastCommittedURL());
       stats.is_media = IsMediaTab(contents);
       stats.is_pinned = model->IsTabPinned(i);
       stats.is_selected = active_model && model->IsTabSelected(i);
@@ -575,62 +698,6 @@ void TabManager::PurgeAndSuspendBackgroundedTabs() {
   }
 }
 
-bool TabManager::CanDiscardTab(int64_t target_web_contents_id) const {
-  TabStripModel* model;
-  int idx = FindTabStripModelById(target_web_contents_id, &model);
-
-  if (idx == -1)
-    return false;
-
-  WebContents* web_contents = model->GetWebContentsAt(idx);
-
-  // Do not discard tabs that don't have a valid URL (most probably they have
-  // just been opened and dicarding them would lose the URL).
-  // TODO(georgesak): Look into a workaround to be able to kill the tab without
-  // losing the pending navigation.
-  if (!web_contents->GetLastCommittedURL().is_valid() ||
-      web_contents->GetLastCommittedURL().is_empty()) {
-    return false;
-  }
-
-  // Do not discard tabs in which the user has entered text in a form, lest that
-  // state gets lost.
-  if (web_contents->GetPageImportanceSignals().had_form_interaction)
-    return false;
-
-  // Do not discard tabs that are playing either playing audio or accessing the
-  // microphone or camera as it's too distruptive to the user experience. Note
-  // that tabs that have recently stopped playing audio by at least
-  // |kAudioProtectionTimeSeconds| seconds are protected as well.
-  if (IsMediaTab(web_contents))
-    return false;
-
-  // Do not discard PDFs as they might contain entry that is not saved and they
-  // don't remember their scrolling positions. See crbug.com/547286 and
-  // crbug.com/65244.
-  // TODO(georgesak): Remove this workaround when the bugs are fixed.
-  if (web_contents->GetContentsMimeType() == "application/pdf")
-    return false;
-
-  // Do not discard a previously discarded tab if that's the desired behavior.
-  if (discard_once_ && GetWebContentsData(web_contents)->DiscardCount() > 0)
-    return false;
-
-  // Do not discard a recently used tab.
-  if (minimum_protection_time_.InSeconds() > 0) {
-    auto delta =
-        NowTicks() - GetWebContentsData(web_contents)->LastInactiveTime();
-    if (delta < minimum_protection_time_)
-      return false;
-  }
-
-  // Do not discard a tab that was explicitly disallowed to.
-  if (!IsTabAutoDiscardable(web_contents))
-    return false;
-
-  return true;
-}
-
 WebContents* TabManager::DiscardWebContentsAt(int index, TabStripModel* model) {
   // Can't discard active index.
   if (model->active_index() == index)
@@ -709,6 +776,44 @@ void TabManager::OnMemoryPressure(
 #endif
 }
 
+void TabManager::TabChangedAt(content::WebContents* contents,
+                              int index,
+                              TabChangeType change_type) {
+  if (change_type != TabChangeType::ALL)
+    return;
+  auto* data = GetWebContentsData(contents);
+  bool old_state = data->IsRecentlyAudible();
+  bool current_state = contents->WasRecentlyAudible();
+  if (old_state != current_state) {
+    data->SetRecentlyAudible(current_state);
+    data->SetLastAudioChangeTime(NowTicks());
+  }
+}
+
+void TabManager::ActiveTabChanged(content::WebContents* old_contents,
+                                  content::WebContents* new_contents,
+                                  int index,
+                                  int reason) {
+  GetWebContentsData(new_contents)->SetDiscardState(false);
+  // If |old_contents| is set, that tab has switched from being active to
+  // inactive, so record the time of that transition.
+  if (old_contents)
+    GetWebContentsData(old_contents)->SetLastInactiveTime(NowTicks());
+}
+
+void TabManager::TabInsertedAt(content::WebContents* contents,
+                               int index,
+                               bool foreground) {
+  // Only interested in background tabs, as foreground tabs get taken care of by
+  // ActiveTabChanged.
+  if (foreground)
+    return;
+
+  // A new background tab is similar to having a tab switch from being active to
+  // inactive.
+  GetWebContentsData(contents)->SetLastInactiveTime(NowTicks());
+}
+
 bool TabManager::IsMediaTab(WebContents* contents) const {
   if (contents->WasRecentlyAudible())
     return true;
@@ -733,51 +838,6 @@ TabManager::WebContentsData* TabManager::GetWebContentsData(
   return web_contents_data;
 }
 
-// static
-bool TabManager::CompareTabStats(const TabStats& first,
-                                 const TabStats& second) {
-  // Being currently selected is most important to protect.
-  if (first.is_selected != second.is_selected)
-    return first.is_selected;
-
-  // Non auto-discardable tabs are more important to protect.
-  if (first.is_auto_discardable != second.is_auto_discardable)
-    return !first.is_auto_discardable;
-
-  // Protect tabs with pending form entries.
-  if (first.has_form_entry != second.has_form_entry)
-    return first.has_form_entry;
-
-  // Protect streaming audio and video conferencing tabs as these are similar to
-  // active tabs.
-  if (first.is_media != second.is_media)
-    return first.is_media;
-
-  // Tab with internal web UI like NTP or Settings are good choices to discard,
-  // so protect non-Web UI and let the other conditionals finish the sort.
-  if (first.is_internal_page != second.is_internal_page)
-    return !first.is_internal_page;
-
-  // Being pinned is important to protect.
-  if (first.is_pinned != second.is_pinned)
-    return first.is_pinned;
-
-  // Being an app is important too, as it's the only visible surface in the
-  // window and should not be discarded.
-  if (first.is_app != second.is_app)
-    return first.is_app;
-
-  // TODO(jamescook): Incorporate sudden_termination_allowed into the sort
-  // order. This is currently not done because pages with unload handlers set
-  // sudden_termination_allowed false, and that covers too many common pages
-  // with ad networks and statistics scripts.  Ideally check for beforeUnload
-  // handlers, which are likely to present a dialog asking if the user wants to
-  // discard state.  crbug.com/123049.
-
-  // Being more recently active is more important.
-  return first.last_active > second.last_active;
-}
-
 TimeTicks TabManager::NowTicks() const {
   if (!test_tick_clock_)
     return TimeTicks::Now();
@@ -884,65 +944,4 @@ bool TabManager::CanOnlyDiscardOnce() {
 #endif
 }
 
-// Things to collect on the browser thread (because TabStripModel isn't thread
-// safe):
-// 1) whether or not a tab is pinned
-// 2) last time a tab was selected
-// 3) is the tab currently selected
-TabStatsList TabManager::GetUnsortedTabStats() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  TabStatsList stats_list;
-  stats_list.reserve(32);  // 99% of users have < 30 tabs open.
-
-  // TODO(chrisha): Move this code to a TabStripModel enumeration delegate!
-  if (!test_tab_strip_models_.empty()) {
-    for (size_t i = 0; i < test_tab_strip_models_.size(); ++i) {
-      AddTabStats(test_tab_strip_models_[i].first,   // tab_strip_model
-                  test_tab_strip_models_[i].second,  // is_app
-                  i == 0,                            // is_active
-                  &stats_list);
-    }
-  } else {
-    // The code here can only be tested under a full browser test.
-    AddTabStats(&stats_list);
-  }
-
-  return stats_list;
-}
-
-void TabManager::AddObserver(TabManagerObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void TabManager::RemoveObserver(TabManagerObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-void TabManager::OnDiscardedStateChange(content::WebContents* contents,
-                                        bool is_discarded) {
-  FOR_EACH_OBSERVER(TabManagerObserver, observers_,
-                    OnDiscardedStateChange(contents, is_discarded));
-}
-
-void TabManager::set_minimum_protection_time_for_tests(
-    base::TimeDelta minimum_protection_time) {
-  minimum_protection_time_ = minimum_protection_time;
-}
-
-void TabManager::OnAutoDiscardableStateChange(content::WebContents* contents,
-                                              bool is_auto_discardable) {
-  FOR_EACH_OBSERVER(
-      TabManagerObserver, observers_,
-      OnAutoDiscardableStateChange(contents, is_auto_discardable));
-}
-
-bool TabManager::IsTabAutoDiscardable(content::WebContents* contents) const {
-  return GetWebContentsData(contents)->IsAutoDiscardable();
-}
-
-void TabManager::SetTabAutoDiscardableState(content::WebContents* contents,
-                                            bool state) {
-  GetWebContentsData(contents)->SetAutoDiscardableState(state);
-}
-
 }  // namespace memory