Don't crash on infobar teardown.

There could be an ordering issue with the teardown
of a tab with an infobar after the infobar change
in r547527. Watch the "infobar manager gone" callback
and ensure a correct order.

For correctness, this makes the change in all the
other places that change used the infobar observer
except for InfoBarObserver, which is changed this
way in https://crrev.com/c/991468 .

BUG=354380, 828552

Change-Id: I21add007c5b2d725dc2985cbd268d3d4674978b6
Reviewed-on: https://chromium-review.googlesource.com/996372Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548246}

chrome/browser/translate/translate_manager_render_view_host_unittest.cc

@@ -13,6 +13,7 @@
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "base/scoped_observer.h"
 #include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
 #include "build/build_config.h"
@@ -213,7 +214,8 @@ class TranslateManagerRenderViewHostTest
   TranslateManagerRenderViewHostTest()
       : pref_callback_(
             base::Bind(&TranslateManagerRenderViewHostTest::OnPreferenceChanged,
-                       base::Unretained(this))) {}
+                       base::Unretained(this))),
+        infobar_observer_(this) {}
 
 #if !defined(USE_AURA)
   // Ensure that we are testing under the bubble UI.
@@ -450,6 +452,10 @@ class TranslateManagerRenderViewHostTest
     removed_infobars_.insert(infobar->delegate());
   }
 
+  void OnManagerShuttingDown(infobars::InfoBarManager* manager) override {
+    infobar_observer_.Remove(manager);
+  }
+
   MOCK_METHOD1(OnPreferenceChanged, void(const std::string&));
 
  protected:
@@ -476,11 +482,11 @@ class TranslateManagerRenderViewHostTest
         ->translate_driver()
         .set_translate_max_reload_attempts(0);
 
-    infobar_service()->AddObserver(this);
+    infobar_observer_.Add(infobar_service());
   }
 
   virtual void TearDown() {
-    infobar_service()->RemoveObserver(this);
+    infobar_observer_.Remove(infobar_service());
 
     ChromeRenderViewHostTestHarness::TearDown();
     TranslateService::ShutdownForTesting();
@@ -542,6 +548,9 @@ class TranslateManagerRenderViewHostTest
   std::unique_ptr<MockTranslateBubbleFactory> bubble_factory_;
   FakePageImpl fake_page_;
 
+  ScopedObserver<infobars::InfoBarManager, infobars::InfoBarManager::Observer>
+      infobar_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(TranslateManagerRenderViewHostTest);
 };
 

chrome/browser/ui/hung_plugin_tab_helper.cc

@@ -194,6 +194,11 @@ void HungPluginTabHelper::OnInfoBarRemoved(infobars::InfoBar* infobar,
   }
 }
 
+void HungPluginTabHelper::OnManagerShuttingDown(
+    infobars::InfoBarManager* manager) {
+  infobar_observer_.Remove(manager);
+}
+
 void HungPluginTabHelper::KillPlugin(int child_id) {
   PluginStateMap::iterator found = hung_plugins_.find(child_id);
   DCHECK(found != hung_plugins_.end());

chrome/browser/ui/hung_plugin_tab_helper.h

@@ -49,6 +49,7 @@ class HungPluginTabHelper
 
   // infobars::InfoBarManager::Observer:
   void OnInfoBarRemoved(infobars::InfoBar* infobar, bool animate) override;
+  void OnManagerShuttingDown(infobars::InfoBarManager* manager) override;
 
   // Called by an infobar when the user selects to kill the plugin.
   void KillPlugin(int child_id);

chrome/test/ppapi/ppapi_test.cc

@@ -74,14 +74,13 @@ void PPAPITestMessageHandler::Reset() {
 PPAPITestBase::InfoBarObserver::InfoBarObserver(PPAPITestBase* test_base)
     : test_base_(test_base),
       expecting_infobar_(false),
-      should_accept_(false) {
-  GetInfoBarService()->AddObserver(this);
+      should_accept_(false),
+      infobar_observer_(this) {
+  infobar_observer_.Add(GetInfoBarService());
 }
 
 PPAPITestBase::InfoBarObserver::~InfoBarObserver() {
   EXPECT_FALSE(expecting_infobar_) << "Missing an expected infobar";
-
-  GetInfoBarService()->RemoveObserver(this);
 }
 
 void PPAPITestBase::InfoBarObserver::ExpectInfoBarAndAccept(
@@ -101,6 +100,11 @@ void PPAPITestBase::InfoBarObserver::OnInfoBarAdded(
       base::Bind(&InfoBarObserver::VerifyInfoBarState, base::Unretained(this)));
 }
 
+void PPAPITestBase::InfoBarObserver::OnManagerShuttingDown(
+    infobars::InfoBarManager* manager) {
+  infobar_observer_.Remove(manager);
+}
+
 void PPAPITestBase::InfoBarObserver::VerifyInfoBarState() {
   InfoBarService* infobar_service = GetInfoBarService();
   EXPECT_EQ(expecting_infobar_ ? 1U : 0U, infobar_service->infobar_count());

chrome/test/ppapi/ppapi_test.h

@@ -9,6 +9,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/scoped_observer.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "components/infobars/core/infobar_manager.h"
 #include "content/public/test/javascript_test_observer.h"
@@ -66,6 +67,7 @@ class PPAPITestBase : public InProcessBrowserTest {
    private:
     // infobars::InfoBarManager::Observer:
     void OnInfoBarAdded(infobars::InfoBar* infobar) override;
+    void OnManagerShuttingDown(infobars::InfoBarManager* manager) override;
 
     InfoBarService* GetInfoBarService();
 
@@ -74,6 +76,9 @@ class PPAPITestBase : public InProcessBrowserTest {
     PPAPITestBase* test_base_;
     bool expecting_infobar_;
     bool should_accept_;
+
+    ScopedObserver<infobars::InfoBarManager, infobars::InfoBarManager::Observer>
+        infobar_observer_;
   };
 
   // Runs the test for a tab given the tab that's already navigated to the