Change infobar creation to use a public static Create() method on the infobar delegate classes. Make constructors as private as possible.

This has several purposes:
* By preventing direct instantiation, it prevents callers from leaking if they create an infobar and don't add it to an InfoBarService.
* By moving decision-making about when to show infobars into these Create() functions, there's a pattern for where such code should go, and caller code becomes simpler and easier to read.
* The two bullets above together mean that for infobars which should only be displayed in certain circumstances, code can't accidentally bypass the decision logic.
* It enables us to eliminate a common InfoBarService* temp on the caller side since the caller no longer needs to both pass the pointer to the infobar _and_ call AddInfoBar() on the pointer.  This was also a somewhat redundant-looking pattern.
* It makes it easier to change the ownership model for infobars in the future by limiting the affected callsites to only the Create() functions.

Note that right now, this still feels pretty redundant since we pass all the same args to Create() functions as constructors most times.  In the new ownership model constructors will no longer need to take InfoBarService*s, which will make this better.

Additionally, this makes AddInfoBar()/ReplaceInfoBar() take scoped_ptr<>s to indicate they're receiving ownership.  This sort of change is easy to make since we only need change the create functions.

This change also has a functional effect: it eliminates some cases where we tried to only show infobars when no other infobars were already showing (discussed and approved by Glen).

BUG=none
TEST=none
Review URL: https://codereview.chromium.org/11644059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@175467 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 29 insertions, 8 deletions

diff --git a/chrome/browser/google/google_url_tracker_unittest.cc b/chrome/browser/google/google_url_tracker_unittest.cc
index 8ad21b7..15bba46 100644
--- a/chrome/browser/google/google_url_tracker_unittest.cc
+++ b/chrome/browser/google/google_url_tracker_unittest.cc
@@ -31,13 +31,25 @@ namespace {
 
 class TestInfoBarDelegate : public GoogleURLTrackerInfoBarDelegate {
  public:
+  // Creates a test delegate and returns it.  Unlike the parent class, this does
+  // not create add the infobar to |infobar_service|, since that "pointer" is
+  // really just a magic number.  Thus there is no InfoBarService ownership of
+  // the returned object; and since the caller doesn't own the returned object,
+  // we rely on |test_harness| cleaning this up eventually in
+  // GoogleURLTrackerTest::OnInfoBarClosed() to avoid leaks.
+  static GoogleURLTrackerInfoBarDelegate* Create(
+      GoogleURLTrackerTest* test_harness,
+      InfoBarService* infobar_service,
+      GoogleURLTracker* google_url_tracker,
+      const GURL& search_url);
+
+ private:
   TestInfoBarDelegate(GoogleURLTrackerTest* test_harness,
                       InfoBarService* infobar_service,
                       GoogleURLTracker* google_url_tracker,
                       const GURL& search_url);
   virtual ~TestInfoBarDelegate();
 
- private:
   // GoogleURLTrackerInfoBarDelegate:
   virtual void Update(const GURL& search_url) OVERRIDE;
   virtual void Close(bool redo_search) OVERRIDE;
@@ -106,7 +118,7 @@ void TestNotificationObserver::Observe(
 class GoogleURLTrackerTest : public testing::Test {
  public:
   // Called by TestInfoBarDelegate::Close().
-  void OnInfoBarClosed(GoogleURLTrackerInfoBarDelegate* infobar,
+  void OnInfoBarClosed(InfoBarDelegate* infobar,
                        InfoBarService* infobar_service);
 
  protected:
@@ -170,9 +182,8 @@ class GoogleURLTrackerTest : public testing::Test {
   std::set<int> unique_ids_seen_;
 };
 
-void GoogleURLTrackerTest::OnInfoBarClosed(
-    GoogleURLTrackerInfoBarDelegate* infobar,
-    InfoBarService* infobar_service) {
+void GoogleURLTrackerTest::OnInfoBarClosed(InfoBarDelegate* infobar,
+                                           InfoBarService* infobar_service) {
   // First, simulate the InfoBarService firing INFOBAR_REMOVED.
   InfoBarRemovedDetails removed_details(infobar, false);
   GoogleURLTracker::EntryMap::const_iterator i =
@@ -185,7 +196,7 @@ void GoogleURLTrackerTest::OnInfoBarClosed(
                      content::Details<InfoBarRemovedDetails>(&removed_details));
 
   // Second, simulate the infobar container closing the infobar in response.
-  infobar->InfoBarClosed();
+  delete infobar;
 }
 
 GoogleURLTrackerTest::GoogleURLTrackerTest()
@@ -386,8 +397,8 @@ GoogleURLTrackerInfoBarDelegate* GoogleURLTrackerTest::CreateTestInfoBar(
     InfoBarService* infobar_service,
     GoogleURLTracker* google_url_tracker,
     const GURL& search_url) {
-  return new TestInfoBarDelegate(this, infobar_service, google_url_tracker,
-                                 search_url);
+  return TestInfoBarDelegate::Create(this, infobar_service, google_url_tracker,
+                                     search_url);
 }
 
 
@@ -395,6 +406,16 @@ GoogleURLTrackerInfoBarDelegate* GoogleURLTrackerTest::CreateTestInfoBar(
 
 namespace {
 
+// static
+GoogleURLTrackerInfoBarDelegate* TestInfoBarDelegate::Create(
+    GoogleURLTrackerTest* test_harness,
+    InfoBarService* infobar_service,
+    GoogleURLTracker* google_url_tracker,
+    const GURL& search_url) {
+  return new TestInfoBarDelegate(test_harness, infobar_service,
+                                 google_url_tracker, search_url);
+}
+
 TestInfoBarDelegate::TestInfoBarDelegate(GoogleURLTrackerTest* test_harness,
                                          InfoBarService* infobar_service,
                                          GoogleURLTracker* google_url_tracker,