A number of issues weren't addressed with the earlier patch for prerender + browsing history, particularly for instant pages.

  - The "remove first entry" option used by instant was not being handled correctly when there was only one committed entry in the NavigationController.

  - Renderer-issued navigations which were committed in the browser but not yet known by the browser/NavigationController were being incorrectly pruned. This did not happen regularly in the prerender case, but does in the instant case, particularly when changing what's typed in the omnibox.

  - Some additional sanity testing to make sure that the message is sent to the correct render process.

  - Additional unit tests are added.

BUG=89798
TEST=NavigationControllerTest.CopyStateFromAndPrune*, RenderViewTest.SetHistoryLengthAndPrune.


Review URL: http://codereview.chromium.org/7618016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96724 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 114 insertions, 14 deletions

diff --git a/content/browser/tab_contents/navigation_controller.cc b/content/browser/tab_contents/navigation_controller.cc
index 0144fef..315a4711 100644
--- a/content/browser/tab_contents/navigation_controller.cc
+++ b/content/browser/tab_contents/navigation_controller.cc
@@ -883,6 +883,14 @@ void NavigationController::CopyStateFrom(const NavigationController& source) {
 
 void NavigationController::CopyStateFromAndPrune(NavigationController* source,
                                                  bool remove_first_entry) {
+  // The SiteInstance and page_id of the last committed entry needs to be
+  // remembered at this point, in case there is only one committed entry
+  // and it is pruned.
+  NavigationEntry* last_committed = GetLastCommittedEntry();
+  SiteInstance* site_instance =
+      last_committed ? last_committed->site_instance() : NULL;
+  int32 minimum_page_id = last_committed ? last_committed->page_id() : -1;
+
   // This code is intended for use when the last entry is the active entry.
   DCHECK((transient_entry_index_ != -1 &&
           transient_entry_index_ == entry_count() - 1) ||
@@ -891,6 +899,16 @@ void NavigationController::CopyStateFromAndPrune(NavigationController* source,
          (!pending_entry_ && last_committed_entry_index_ == entry_count() - 1));
 
   if (remove_first_entry && entry_count()) {
+    // If there is only one committed entry and |remove_first_entry| is true,
+    // it needs to be pruned. This is accomplished by specifying a larger
+    // |minimum_page_id| than the committed entry's page_id in the
+    // ViewMsg_SetHistoryLengthAndPrune message. However, any pages which are
+    // committed between now and when the RenderView handles the message will
+    // need to be retained. Both constraints can be met by incrementing the
+    // |minimum_page_id| by 1.
+    DCHECK(minimum_page_id >= 0);
+    if (entry_count() == 1)
+      ++minimum_page_id;
     // Save then restore the pending entry (RemoveEntryAtIndexInternal chucks
     // the pending entry).
     NavigationEntry* pending_entry = pending_entry_;
@@ -932,8 +950,9 @@ void NavigationController::CopyStateFromAndPrune(NavigationController* source,
       last_committed_entry_index_--;
   }
 
-  // Update the history in the RenderView.
-  tab_contents_->SetHistoryLengthAndClear(max_source_index);
+  tab_contents_->SetHistoryLengthAndPrune(site_instance,
+                                          max_source_index,
+                                          minimum_page_id);
 }
 
 void NavigationController::PruneAllButActive() {
diff --git a/content/browser/tab_contents/navigation_controller_unittest.cc b/content/browser/tab_contents/navigation_controller_unittest.cc
index f7992c2..4e1ec10 100644
--- a/content/browser/tab_contents/navigation_controller_unittest.cc
+++ b/content/browser/tab_contents/navigation_controller_unittest.cc
@@ -1923,6 +1923,9 @@ TEST_F(NavigationControllerTest, CopyStateFromAndPrune) {
   scoped_ptr<TestTabContents> other_contents(CreateTestTabContents());
   NavigationController& other_controller = other_contents->controller();
   other_contents->NavigateAndCommit(url3);
+  other_contents->ExpectSetHistoryLengthAndPrune(
+      other_controller.GetEntryAtIndex(0)->site_instance(), 2,
+      other_controller.GetEntryAtIndex(0)->page_id());
   other_controller.CopyStateFromAndPrune(&controller(), false);
 
   // other_controller should now contain the 3 urls: url1, url2 and url3.
@@ -1949,6 +1952,7 @@ TEST_F(NavigationControllerTest, CopyStateFromAndPrune2) {
 
   scoped_ptr<TestTabContents> other_contents(CreateTestTabContents());
   NavigationController& other_controller = other_contents->controller();
+  other_contents->ExpectSetHistoryLengthAndPrune(NULL, 1, -1);
   other_controller.CopyStateFromAndPrune(&controller(), false);
 
   // other_controller should now contain the 1 url: url1.
@@ -1974,6 +1978,7 @@ TEST_F(NavigationControllerTest, CopyStateFromAndPrune3) {
   scoped_ptr<TestTabContents> other_contents(CreateTestTabContents());
   NavigationController& other_controller = other_contents->controller();
   other_controller.LoadURL(url3, GURL(), PageTransition::TYPED);
+  other_contents->ExpectSetHistoryLengthAndPrune(NULL, 1, -1);
   other_controller.CopyStateFromAndPrune(&controller(), false);
 
   // other_controller should now contain 1 entry for url1, and a pending entry
@@ -2000,6 +2005,7 @@ TEST_F(NavigationControllerTest, CopyStateFromAndPrune4) {
 
   scoped_ptr<TestTabContents> other_contents(CreateTestTabContents());
   NavigationController& other_controller = other_contents->controller();
+  other_contents->ExpectSetHistoryLengthAndPrune(NULL, 1, -1);
   other_controller.CopyStateFromAndPrune(&controller(), true);
 
   // other_controller should now contain 1 entry for url1.
@@ -2025,6 +2031,10 @@ TEST_F(NavigationControllerTest, CopyStateFromAndPrune5) {
   scoped_ptr<TestTabContents> other_contents(CreateTestTabContents());
   NavigationController& other_controller = other_contents->controller();
   other_contents->NavigateAndCommit(url2);
+  other_contents->ExpectSetHistoryLengthAndPrune(
+      other_controller.GetEntryAtIndex(0)->site_instance(),
+      1,
+      other_controller.GetEntryAtIndex(0)->page_id() + 1);
   other_controller.CopyStateFromAndPrune(&controller(), true);
 
   // other_controller should now contain 1 entry, url1.
@@ -2050,6 +2060,10 @@ TEST_F(NavigationControllerTest, CopyStateFromAndPrune6) {
   NavigationController& other_controller = other_contents->controller();
   other_contents->NavigateAndCommit(url2);
   other_controller.LoadURL(url3, GURL(), PageTransition::TYPED);
+  other_contents->ExpectSetHistoryLengthAndPrune(
+      other_controller.GetEntryAtIndex(0)->site_instance(),
+      1,
+      other_controller.GetEntryAtIndex(0)->page_id() + 1);
   other_controller.CopyStateFromAndPrune(&controller(), true);
 
   // other_controller should now contain 2 entries: url1, and url3.
diff --git a/content/browser/tab_contents/tab_contents.cc b/content/browser/tab_contents/tab_contents.cc
index 1fdccbf..b14a4cc 100644
--- a/content/browser/tab_contents/tab_contents.cc
+++ b/content/browser/tab_contents/tab_contents.cc
@@ -596,12 +596,29 @@ bool TabContents::NavigateToEntry(
   return true;
 }
 
-void TabContents::SetHistoryLengthAndClear(int history_length) {
+void TabContents::SetHistoryLengthAndPrune(const SiteInstance* site_instance,
+                                           int history_length,
+                                           int32 minimum_page_id) {
+  // SetHistoryLengthAndPrune doesn't handle pending cross-site navigations
+  // cleanly. Since it's only used when swapping in instant and prerendered
+  // TabContents, checks are done at a higher level to ensure that the pages
+  // are not swapped in during this case.
+  if (render_manager_.pending_render_view_host()) {
+    NOTREACHED();
+    return;
+  }
   RenderViewHost* rvh = render_view_host();
-  if (!rvh)
+  if (!rvh) {
+    NOTREACHED();
     return;
-  rvh->Send(new ViewMsg_SetHistoryLengthAndClear(rvh->routing_id(),
-                                                 history_length));
+  }
+  if (site_instance && rvh->site_instance() != site_instance) {
+    NOTREACHED();
+    return;
+  }
+  rvh->Send(new ViewMsg_SetHistoryLengthAndPrune(rvh->routing_id(),
+                                                 history_length,
+                                                 minimum_page_id));
 }
 
 void TabContents::Stop() {
diff --git a/content/browser/tab_contents/tab_contents.h b/content/browser/tab_contents/tab_contents.h
index 13b5c28..3f416e4 100644
--- a/content/browser/tab_contents/tab_contents.h
+++ b/content/browser/tab_contents/tab_contents.h
@@ -626,9 +626,10 @@ class TabContents : public PageNavigator,
   // Sets the history for this tab_contents to |history_length| entries, and
   // moves the current page_id to the last entry in the list if it's valid.
   // This is mainly used when a prerendered page is swapped into the current
-  // tab.
-  void SetHistoryLengthAndClear(int history_length);
-
+  // tab. The method is virtual for testing.
+  virtual void SetHistoryLengthAndPrune(const SiteInstance* site_instance,
+                                        int merge_history_length,
+                                        int32 minimum_page_id);
 
   // Misc non-view stuff -------------------------------------------------------
 
diff --git a/content/browser/tab_contents/test_tab_contents.cc b/content/browser/tab_contents/test_tab_contents.cc
index 4252114..13cb1d9 100644
--- a/content/browser/tab_contents/test_tab_contents.cc
+++ b/content/browser/tab_contents/test_tab_contents.cc
@@ -17,7 +17,14 @@ TestTabContents::TestTabContents(content::BrowserContext* browser_context,
                                  SiteInstance* instance)
     : TabContents(browser_context, instance, MSG_ROUTING_NONE, NULL, NULL),
       transition_cross_site(false),
-      delegate_view_override_(NULL) {
+      delegate_view_override_(NULL),
+      expect_set_history_length_and_prune_(false),
+      expect_set_history_length_and_prune_site_instance_(NULL),
+      expect_set_history_length_and_prune_history_length_(0),
+      expect_set_history_length_and_prune_min_page_id_(-1) {
+}
+
+TestTabContents::~TestTabContents() {
 }
 
 TestRenderViewHost* TestTabContents::pending_rvh() const {
@@ -90,3 +97,23 @@ RenderViewHostDelegate::View* TestTabContents::GetViewDelegate() {
     return delegate_view_override_;
   return TabContents::GetViewDelegate();
 }
+
+void TestTabContents::ExpectSetHistoryLengthAndPrune(
+    const SiteInstance* site_instance,
+    int history_length,
+    int32 min_page_id) {
+  expect_set_history_length_and_prune_ = true;
+  expect_set_history_length_and_prune_site_instance_ = site_instance;
+  expect_set_history_length_and_prune_history_length_ = history_length;
+  expect_set_history_length_and_prune_min_page_id_ = min_page_id;
+}
+
+void TestTabContents::SetHistoryLengthAndPrune(
+    const SiteInstance* site_instance, int history_length, int32 min_page_id) {
+  EXPECT_TRUE(expect_set_history_length_and_prune_);
+  expect_set_history_length_and_prune_ = false;
+  EXPECT_EQ(expect_set_history_length_and_prune_site_instance_, site_instance);
+  EXPECT_EQ(expect_set_history_length_and_prune_history_length_,
+            history_length);
+  EXPECT_EQ(expect_set_history_length_and_prune_min_page_id_, min_page_id);
+}
diff --git a/content/browser/tab_contents/test_tab_contents.h b/content/browser/tab_contents/test_tab_contents.h
index fb7b1bc..72170ab 100644
--- a/content/browser/tab_contents/test_tab_contents.h
+++ b/content/browser/tab_contents/test_tab_contents.h
@@ -17,6 +17,7 @@ class TestTabContents : public TabContents {
  public:
   TestTabContents(content::BrowserContext* browser_context,
                   SiteInstance* instance);
+  virtual ~TestTabContents();
 
   TestRenderViewHost* pending_rvh() const;
 
@@ -42,12 +43,12 @@ class TestTabContents : public TabContents {
 
   // Prevent interaction with views.
   virtual bool CreateRenderViewForRenderManager(
-      RenderViewHost* render_view_host);
-  virtual void UpdateRenderViewSizeForRenderManager() {}
+      RenderViewHost* render_view_host) OVERRIDE;
+  virtual void UpdateRenderViewSizeForRenderManager() OVERRIDE {}
 
   // Returns a clone of this TestTabContents. The returned object is also a
   // TestTabContents. The caller owns the returned object.
-  virtual TabContents* Clone();
+  virtual TabContents* Clone() OVERRIDE;
 
   // Creates a pending navigation to the given URL with the default parameters
   // and then commits the load with a page ID one larger than any seen. This
@@ -67,12 +68,33 @@ class TestTabContents : public TabContents {
   bool transition_cross_site;
 
   // Allow mocking of the RenderViewHostDelegate::View.
-  virtual RenderViewHostDelegate::View* GetViewDelegate();
+  virtual RenderViewHostDelegate::View* GetViewDelegate() OVERRIDE;
   void set_view_delegate(RenderViewHostDelegate::View* view) {
     delegate_view_override_ = view;
   }
+
+  // Establish expected arguments for |SetHistoryLengthAndPrune()|. When
+  // |SetHistoryLengthAndPrune()| is called, the arguments are compared
+  // with the expected arguments specified here.
+  void ExpectSetHistoryLengthAndPrune(const SiteInstance* site_instance,
+                                      int history_length,
+                                      int32 min_page_id);
+
+  // Compares the arguments passed in with the expected arguments passed in
+  // to |ExpectSetHistoryLengthAndPrune()|.
+  virtual void SetHistoryLengthAndPrune(const SiteInstance* site_instance,
+                                        int history_length,
+                                        int32 min_page_id) OVERRIDE;
+
  private:
   RenderViewHostDelegate::View* delegate_view_override_;
+
+  // Expectations for arguments of |SetHistoryLengthAndPrune()|.
+  bool expect_set_history_length_and_prune_;
+  scoped_refptr<const SiteInstance>
+    expect_set_history_length_and_prune_site_instance_;
+  int expect_set_history_length_and_prune_history_length_;
+  int32 expect_set_history_length_and_prune_min_page_id_;
 };
 
 #endif  // CONTENT_BROWSER_TAB_CONTENTS_TEST_TAB_CONTENTS_H_