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

chrome/browser/memory/tab_manager_web_contents_data.cc

Index: chrome/browser/memory/tab_manager_web_contents_data.cc
diff --git a/chrome/browser/memory/tab_manager_web_contents_data.cc b/chrome/browser/memory/tab_manager_web_contents_data.cc
index d4efa76a7b5a02259ee598c286515081be369c49..42e31f7e9f002b41ff5983d888e8d1040a5c2a0f 100644
--- a/chrome/browser/memory/tab_manager_web_contents_data.cc
+++ b/chrome/browser/memory/tab_manager_web_contents_data.cc
@@ -11,116 +11,82 @@
 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));
-
-  // 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(content::WebContents* web_contents)
+    : WebContentsObserver(web_contents) {}
 
-  return discard_state;
-}
+TabManager::WebContentsData::~WebContentsData() {}
 
-// static
-void TabManager::WebContentsData::Set(WebContents* web_contents,
-                                      WebContentsData* state) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  web_contents->SetUserData(&kDiscardStateKey, state);
+void TabManager::WebContentsData::DidStartLoading() {
+  // Marks the tab as no longer discarded if it has been reloaded from another
+  // source (ie: context menu).
+  SetDiscardState(false);
 }
 
-// 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;
-}
-
-// static
-bool TabManager::WebContentsData::IsDiscarded(WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)->is_discarded_;
+bool TabManager::WebContentsData::IsDiscarded() {
+  return tab_data_.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) {
+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() - discard_state->last_discard_time_;
+    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 (!discard_state->is_discarded_ && state) {
+  } else if (!tab_data_.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();
+    tab_data_.last_discard_time_ = base::TimeTicks::Now();
   }
 
-  discard_state->is_discarded_ = state;
+  tab_data_.is_discarded_ = state;
 }
 
-// static
-int TabManager::WebContentsData::DiscardCount(WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)->discard_count_;
+int TabManager::WebContentsData::DiscardCount() {
+  return tab_data_.discard_count_;
 }
 
-// static
-void TabManager::WebContentsData::IncrementDiscardCount(
-    WebContents* web_contents) {
-  TabManager::WebContentsData::Get(web_contents)->discard_count_++;
+void TabManager::WebContentsData::IncrementDiscardCount() {
+  tab_data_.discard_count_++;
 }
 
-// static
-bool TabManager::WebContentsData::IsRecentlyAudible(
-    content::WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)->is_recently_audible_;
+bool TabManager::WebContentsData::IsRecentlyAudible() {
+  return tab_data_.is_recently_audible_;
 }
 
-// static
-void TabManager::WebContentsData::SetRecentlyAudible(
-    content::WebContents* web_contents,
-    bool state) {
-  TabManager::WebContentsData::Get(web_contents)->is_recently_audible_ = state;
+void TabManager::WebContentsData::SetRecentlyAudible(bool state) {
+  tab_data_.is_recently_audible_ = state;
 }
 
-// static
-TimeTicks TabManager::WebContentsData::LastAudioChangeTime(
-    content::WebContents* web_contents) {
-  return TabManager::WebContentsData::Get(web_contents)
-      ->last_audio_change_time_;
+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::SetLastAudioChangeTime(
-    content::WebContents* web_contents,
-    TimeTicks timestamp) {
-  TabManager::WebContentsData::Get(web_contents)->last_audio_change_time_ =
-      timestamp;
+void TabManager::WebContentsData::CopyState(
+    content::WebContents* old_contents,
+    content::WebContents* new_contents) {
+  // 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_;
+  }
 }
 
-TabManager::WebContentsData::WebContentsData()
+TabManager::WebContentsData::Data::Data()
     : is_discarded_(false),
       discard_count_(0),
       is_recently_audible_(false),