[TabManager] Move remaining discard logic from TabStripModel to TabManager.

chrome/browser/memory/tab_manager_web_contents_data.cc

 // Copyright 2015 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.
 
 #include "chrome/browser/memory/tab_manager_web_contents_data.h"
 
 #include "base/metrics/histogram.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 
 using base::TimeTicks;
 using content::WebContents;
 
-namespace {
-
-const char kDiscardStateKey[] = "WebContentsData";
-
-}  // namespace
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(memory::TabManager::WebContentsData);
 
 namespace memory {
 
-// static
-TabManager::WebContentsData* TabManager::WebContentsData::Get(
-    WebContents* web_contents) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  TabManager::WebContentsData* discard_state = static_cast<WebContentsData*>(
-      web_contents->GetUserData(&kDiscardStateKey));
+TabManager::WebContentsData::WebContentsData(content::WebContents* web_contents)
+    : WebContentsObserver(web_contents) {}
 
-  // If this function is called, we probably need to query/change the discard
-  // state. Let's go ahead a add one.
-  if (!discard_state) {
-    discard_state = new WebContentsData;
-    web_contents->SetUserData(&kDiscardStateKey, discard_state);
+TabManager::WebContentsData::~WebContentsData() {}
+
+void TabManager::WebContentsData::DidStartLoading() {
+  // Marks the tab as no longer discarded if it has been reloaded from another
+  // source (ie: context menu).
+  SetDiscardState(false);
+}
+
+bool TabManager::WebContentsData::IsDiscarded() {
+  return tab_data_.is_discarded_;
+}
+
+void TabManager::WebContentsData::SetDiscardState(bool state) {
+  if (tab_data_.is_discarded_ && !state) {
+    static int reload_count = 0;
+    UMA_HISTOGRAM_CUSTOM_COUNTS("TabManager.Discarding.ReloadCount",
+                                ++reload_count, 1, 1000, 50);
+    auto delta = base::TimeTicks::Now() - tab_data_.last_discard_time_;
+    // Capped to one day for now, will adjust if necessary.
+    UMA_HISTOGRAM_CUSTOM_TIMES("TabManager.Discarding.DiscardToReloadTime",
+                               delta, base::TimeDelta::FromSeconds(1),
+                               base::TimeDelta::FromDays(1), 100);
+  } else if (!tab_data_.is_discarded_ && state) {
+    static int discard_count = 0;
+    UMA_HISTOGRAM_CUSTOM_COUNTS("TabManager.Discarding.DiscardCount",
+                                ++discard_count, 1, 1000, 50);
+    tab_data_.last_discard_time_ = base::TimeTicks::Now();
   }
 
-  return discard_state;
+  tab_data_.is_discarded_ = state;
 }
 
-// static
-void TabManager::WebContentsData::Set(WebContents* web_contents,
-                                      WebContentsData* state) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  web_contents->SetUserData(&kDiscardStateKey, state);
+int TabManager::WebContentsData::DiscardCount() {
+  return tab_data_.discard_count_;
+}
+
+void TabManager::WebContentsData::IncrementDiscardCount() {
+  tab_data_.discard_count_++;
+}
+
+bool TabManager::WebContentsData::IsRecentlyAudible() {
+  return tab_data_.is_recently_audible_;
+}
+
+void TabManager::WebContentsData::SetRecentlyAudible(bool state) {
+  tab_data_.is_recently_audible_ = state;
+}
+
+TimeTicks TabManager::WebContentsData::LastAudioChangeTime() {
+  return tab_data_.last_audio_change_time_;
+}
+
+void TabManager::WebContentsData::SetLastAudioChangeTime(TimeTicks timestamp) {
+  tab_data_.last_audio_change_time_ = timestamp;
 }
 
 // static
 void TabManager::WebContentsData::CopyState(
     content::WebContents* old_contents,
     content::WebContents* new_contents) {
-  WebContentsData* old_state = Get(old_contents);
-  WebContentsData* new_State = Get(new_contents);
-  *new_State = *old_state;
+  // Only copy if an existing state is found.
+  if (FromWebContents(old_contents)) {
+    CreateForWebContents(new_contents);
+    FromWebContents(new_contents)->tab_data_ =
+        FromWebContents(old_contents)->tab_data_;
+  }
 }
 
-// static
-bool TabManager::WebContentsData::IsDiscarded(WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)->is_discarded_;
-}
-
-// static
-void TabManager::WebContentsData::SetDiscardState(WebContents* web_contents,
-                                                  bool state) {
-  WebContentsData* discard_state =
-      TabManager::WebContentsData::Get(web_contents);
-  if (discard_state->is_discarded_ && !state) {
-    static int reload_count = 0;
-    UMA_HISTOGRAM_CUSTOM_COUNTS("TabManager.Discarding.ReloadCount",
-                                ++reload_count, 1, 1000, 50);
-    auto delta = base::TimeTicks::Now() - discard_state->last_discard_time_;
-    // Capped to one day for now, will adjust if necessary.
-    UMA_HISTOGRAM_CUSTOM_TIMES("TabManager.Discarding.DiscardToReloadTime",
-                               delta, base::TimeDelta::FromSeconds(1),
-                               base::TimeDelta::FromDays(1), 100);
-  } else if (!discard_state->is_discarded_ && state) {
-    static int discard_count = 0;
-    UMA_HISTOGRAM_CUSTOM_COUNTS("TabManager.Discarding.DiscardCount",
-                                ++discard_count, 1, 1000, 50);
-    discard_state->last_discard_time_ = base::TimeTicks::Now();
-  }
-
-  discard_state->is_discarded_ = state;
-}
-
-// static
-int TabManager::WebContentsData::DiscardCount(WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)->discard_count_;
-}
-
-// static
-void TabManager::WebContentsData::IncrementDiscardCount(
-    WebContents* web_contents) {
-  TabManager::WebContentsData::Get(web_contents)->discard_count_++;
-}
-
-// static
-bool TabManager::WebContentsData::IsRecentlyAudible(
-    content::WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)->is_recently_audible_;
-}
-
-// static
-void TabManager::WebContentsData::SetRecentlyAudible(
-    content::WebContents* web_contents,
-    bool state) {
-  TabManager::WebContentsData::Get(web_contents)->is_recently_audible_ = state;
-}
-
-// static
-TimeTicks TabManager::WebContentsData::LastAudioChangeTime(
-    content::WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)
-      ->last_audio_change_time_;
-}
-
-// static
-void TabManager::WebContentsData::SetLastAudioChangeTime(
-    content::WebContents* web_contents,
-    TimeTicks timestamp) {
-  TabManager::WebContentsData::Get(web_contents)->last_audio_change_time_ =
-      timestamp;
-}
-
-TabManager::WebContentsData::WebContentsData()
+TabManager::WebContentsData::Data::Data()
     : is_discarded_(false),
       discard_count_(0),
       is_recently_audible_(false),
       last_audio_change_time_(TimeTicks::UnixEpoch()) {}
 
 }  // namespace memory