[Media Router] Clean up issues related code.

chrome/browser/media/router/issue_manager.cc

Index: chrome/browser/media/router/issue_manager.cc
diff --git a/chrome/browser/media/router/issue_manager.cc b/chrome/browser/media/router/issue_manager.cc
index d3cb9d4f3b5a18fd30765c7c8eeaa24d20718e2d..5068cd230bc65ee5aac30f0557d8ff5a2209fae7 100644
--- a/chrome/browser/media/router/issue_manager.cc
+++ b/chrome/browser/media/router/issue_manager.cc
@@ -10,7 +10,7 @@
 
 namespace media_router {
 
-IssueManager::IssueManager() {
+IssueManager::IssueManager() : top_issue_(nullptr) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 }
 
@@ -20,11 +20,9 @@ IssueManager::~IssueManager() {
 
 void IssueManager::AddIssue(const Issue& issue) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  for (const Issue& next_issue : issues_) {
-    if (next_issue.Equals(issue)) {
-      return;
-    }
-  }
+  if (ContainsValue(issues_, issue))
+    return;
+
   issues_.push_back(issue);
   MaybeUpdateTopIssue();
 }
@@ -53,9 +51,9 @@ void IssueManager::ClearAllIssues() {
 void IssueManager::ClearGlobalIssues() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   issues_.erase(
-      std::remove_if(issues_.begin(), issues_.end(), [](const Issue& issue) {
-        return issue.is_global();
-      }), issues_.end());
+      std::remove_if(issues_.begin(), issues_.end(),
+                     [](const Issue& issue) { return issue.IsGlobal(); }),
+      issues_.end());
   MaybeUpdateTopIssue();
 }
 
@@ -75,15 +73,8 @@ void IssueManager::RegisterObserver(IssuesObserver* observer) {
   DCHECK(!issues_observers_.HasObserver(observer));
 
   issues_observers_.AddObserver(observer);
-  if (top_issue_id_.empty())
-    return;
-
-  // Find the current top issue and report it to the observer.
-  for (const auto& next_issue : issues_) {
-    if (next_issue.id() == top_issue_id_) {
-      observer->OnIssueUpdated(&next_issue);
-    }
-  }
+  if (top_issue_)
+    observer->OnIssueUpdated(top_issue_);
 }
 
 void IssueManager::UnregisterObserver(IssuesObserver* observer) {
@@ -93,29 +84,22 @@ void IssueManager::UnregisterObserver(IssuesObserver* observer) {
 
 void IssueManager::MaybeUpdateTopIssue() {
   const Issue* new_top_issue = nullptr;
-
-  if (issues_.empty()) {
-    FOR_EACH_OBSERVER(IssuesObserver, issues_observers_,
-                      OnIssueUpdated(new_top_issue));
-    return;
+  if (!issues_.empty()) {
+    // Select the first blocking issue in the list of issues.
+    // If there are none, simply select the first issue in the list.
+    auto it =
+        std::find_if(issues_.begin(), issues_.end(),
+                     [](const Issue& issue) { return issue.IsBlocking(); });
+    if (it == issues_.end())
+      it = issues_.begin();
+
+    new_top_issue = &*it;
   }
-
-  // Select the first blocking issue in the list of issues.
-  // If there are none, simply select the first issue in the list.
-  new_top_issue = &(issues_.front());
-  for (const auto& issue : issues_) {
-    // The first blocking issue is of higher priority than the first issue.
-    if (issue.is_blocking()) {
-      new_top_issue = &issue;
-      break;
-    }
-  }
-
   // If we've found a new top issue, then report it via the observer.
-  if (new_top_issue->id() != top_issue_id_) {
-    top_issue_id_ = new_top_issue->id();
+  if (new_top_issue != top_issue_) {
+    top_issue_ = new_top_issue;
     FOR_EACH_OBSERVER(IssuesObserver, issues_observers_,
-                      OnIssueUpdated(new_top_issue));
+                      OnIssueUpdated(top_issue_));
   }
 }