OOPIF: Support session restore by combining/splitting frame states.

content/browser/frame_host/navigation_entry_impl.cc

Index: content/browser/frame_host/navigation_entry_impl.cc
diff --git a/content/browser/frame_host/navigation_entry_impl.cc b/content/browser/frame_host/navigation_entry_impl.cc
index 694985aca8d0ad0a52054082f2eea5f4edd0f5db..44e479ec33c9550a3d11840cc65537753df94395 100644
--- a/content/browser/frame_host/navigation_entry_impl.cc
+++ b/content/browser/frame_host/navigation_entry_impl.cc
@@ -17,6 +17,12 @@
 #include "content/public/common/url_constants.h"
 #include "ui/gfx/text_elider.h"
 
+using base::UTF16ToUTF8;
+
+namespace content {
+
+namespace {
+
 // Use this to get a new unique ID for a NavigationEntry during construction.
 // The returned ID is guaranteed to be nonzero (which is the "no ID" indicator).
 static int GetUniqueIDInConstructor() {
@@ -24,7 +30,43 @@ static int GetUniqueIDInConstructor() {
   return ++unique_id_counter;
 }
 
-namespace content {
+void RecursivelyGenerateFrameEntries(const ExplodedFrameState& state,
+                                     NavigationEntryImpl::TreeNode* node) {
+  node->frame_entry = new FrameNavigationEntry(
+      -1, UTF16ToUTF8(state.target.string()), state.item_sequence_number,
+      state.document_sequence_number, nullptr, GURL(state.url_string.string()),
+      Referrer(GURL(state.referrer.string()), state.referrer_policy));
+
+  node->frame_entry->set_frame_state(state);
+
+  for (const ExplodedFrameState& child_state : state.children) {
+    NavigationEntryImpl::TreeNode* child_node =
+        new NavigationEntryImpl::TreeNode(nullptr);
+    node->children.push_back(child_node);
+    RecursivelyGenerateFrameEntries(child_state, child_node);
+  }
+}
+
+void RecursivelyGenerateFrameState(
+    NavigationEntryImpl::TreeNode* node,
+    ExplodedFrameState* state,
+    std::vector<base::NullableString16>* referenced_files) {
+  // Copy the FrameNavigationEntry's frame state into the destination state.
+  *state = node->frame_entry->frame_state();
+
+  // TODO(creis): Copy the referenced files from frame_entry into
+  // referenced_files (which is from PageState).  Need to implement helper.
+  // ToNullableString16Vector(node->frame_entry->referenced_files(),
+  //                          referenced_files);
+
+  state->children.resize(node->children.size());
+  for (size_t i = 0; i < node->children.size(); ++i) {
+    RecursivelyGenerateFrameState(node->children[i], &state->children[i],
+                                  referenced_files);
+  }
+}
+
+}  // namespace
 
 int NavigationEntryImpl::kInvalidBindings = -1;
 
@@ -180,22 +222,45 @@ const base::string16& NavigationEntryImpl::GetTitle() const {
 }
 
 void NavigationEntryImpl::SetPageState(const PageState& state) {
-  frame_tree_->frame_entry->set_page_state(state);
+  page_state_ = state;
 
-  if (SiteIsolationPolicy::UseSubframeNavigationEntries()) {
-    // Also get the root ISN and DSN out of the PageState.
-    ExplodedPageState exploded_state;
-    if (!DecodePageState(state.ToEncodedData(), &exploded_state))
-      return;
-    frame_tree_->frame_entry->set_item_sequence_number(
-        exploded_state.top.item_sequence_number);
-    frame_tree_->frame_entry->set_document_sequence_number(
-        exploded_state.top.document_sequence_number);
+  if (!SiteIsolationPolicy::UseSubframeNavigationEntries())
+    return;
+
+  // This should only be called when restoring a NavigationEntry, so there
+  // should be no subframe FrameNavigationEntries yet.
+  DCHECK_EQ(0U, frame_tree_->children.size());
+
+  ExplodedPageState exploded_state;
+  if (!DecodePageState(state.ToEncodedData(), &exploded_state)) {
+    // Give up and set an empty ExplodedFrameState on the main frame.
+    frame_tree_->frame_entry->set_frame_state(ExplodedFrameState());
+    return;
   }
+
+  RecursivelyGenerateFrameEntries(exploded_state.top, frame_tree_.get());
 }
 
 const PageState& NavigationEntryImpl::GetPageState() const {
-  return frame_tree_->frame_entry->page_state();
+  return page_state_;
+}
+
+void NavigationEntryImpl::UpdatePageState() {
+  // When we're using subframe entries, each FrameNavigationEntry has a
+  // frame-specific PageState.  We combine these into an ExplodedPageState tree
+  // and generate a full PageState from it.
+  DCHECK(SiteIsolationPolicy::UseSubframeNavigationEntries());
+  ExplodedPageState exploded_state;
+  RecursivelyGenerateFrameState(frame_tree_.get(), &exploded_state.top,
+                                &exploded_state.referenced_files);
+
+  std::string encoded_data;
+  if (!EncodePageState(exploded_state, &encoded_data)) {
+    page_state_ = PageState();
+    return;
+  }
+
+  page_state_ = PageState::CreateFromEncodedData(encoded_data);
 }
 
 void NavigationEntryImpl::SetPageID(int page_id) {
@@ -518,10 +583,17 @@ RequestNavigationParams NavigationEntryImpl::ConstructRequestNavigationParams(
     current_offset_to_send = -1;
     current_length_to_send = 0;
   }
+
+  // Use the actual PageState in default Chrome, and only send the frame state
+  // in OOPIF modes.
+  PageState page_state = SiteIsolationPolicy::UseSubframeNavigationEntries()
+                             ? PageState()
+                             : GetPageState();
+
   return RequestNavigationParams(
       GetIsOverridingUserAgent(), redirects, GetCanLoadLocalResources(),
-      base::Time::Now(), frame_entry.page_state(), GetPageID(), GetUniqueID(),
-      is_same_document_history_load, has_committed_real_load,
+      base::Time::Now(), page_state, frame_entry.frame_state(), GetPageID(),
+      GetUniqueID(), is_same_document_history_load, has_committed_real_load,
       intended_as_new_entry, pending_offset_to_send, current_offset_to_send,
       current_length_to_send, should_clear_history_list());
 }
@@ -555,7 +627,7 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
     SiteInstanceImpl* site_instance,
     const GURL& url,
     const Referrer& referrer,
-    const PageState& page_state) {
+    const ExplodedFrameState& frame_state) {
   // We should already have a TreeNode for the parent node by the time this node
   // commits.  Find it first.
   DCHECK(frame_tree_node->parent());
@@ -574,7 +646,7 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
       // Update the existing FrameNavigationEntry (e.g., for replaceState).
       child->frame_entry->UpdateEntry(frame_unique_name, item_sequence_number,
                                       document_sequence_number, site_instance,
-                                      url, referrer, page_state);
+                                      url, referrer, frame_state);
       return;
     }
   }
@@ -585,7 +657,7 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
   FrameNavigationEntry* frame_entry = new FrameNavigationEntry(
       frame_tree_node_id, frame_unique_name, item_sequence_number,
       document_sequence_number, site_instance, url, referrer);
-  frame_entry->set_page_state(page_state);
+  frame_entry->set_frame_state(frame_state);
   parent_node->children.push_back(
       new NavigationEntryImpl::TreeNode(frame_entry));
 }