Add is_srcdoc to FrameNavigationEntry and restore about::srcdoc URL.

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 b450e8ec3ae6cf7ba5397ba32c8053193cd522e2..cc9eb7145fd9c26e11e587c395b71087a12548a5 100644
--- a/content/browser/frame_host/navigation_entry_impl.cc
+++ b/content/browser/frame_host/navigation_entry_impl.cc
@@ -45,12 +45,15 @@ void RecursivelyGenerateFrameEntries(
     const ExplodedFrameState& state,
     const std::vector<base::NullableString16>& referenced_files,
     NavigationEntryImpl::TreeNode* node) {
+  GURL renderer_url(state.url_string.string());
+  bool is_srcdoc = (renderer_url == GURL(content::kAboutSrcDocURL));
+  GURL browser_url = is_srcdoc ? GURL(url::kAboutBlankURL) : renderer_url;
+
   node->frame_entry = new FrameNavigationEntry(
       UTF16ToUTF8(state.target.string()), state.item_sequence_number,
-      state.document_sequence_number, nullptr, nullptr,
-      GURL(state.url_string.string()),
-      Referrer(GURL(state.referrer.string()), state.referrer_policy), "GET",
-      -1);
+      state.document_sequence_number, nullptr, nullptr, browser_url,
+      Referrer(GURL(state.referrer.string()), state.referrer_policy), "GET", -1,
+      is_srcdoc);
 
   // Set a single-frame PageState on the entry.
   ExplodedPageState page_state;
@@ -260,7 +263,8 @@ NavigationEntryImpl::NavigationEntryImpl(
                                                         url,
                                                         referrer,
                                                         "GET",
-                                                        -1))),
+                                                        -1,
+                                                        false))),
       unique_id_(GetUniqueIDInConstructor()),
       bindings_(kInvalidBindings),
       page_type_(PAGE_TYPE_NORMAL),
@@ -798,7 +802,8 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
     const std::vector<GURL>& redirect_chain,
     const PageState& page_state,
     const std::string& method,
-    int64_t post_id) {
+    int64_t post_id,
+    bool is_srcdoc) {
   // If this is called for the main frame, the FrameNavigationEntry is
   // guaranteed to exist, so just update it directly and return.
   if (frame_tree_node->IsMainFrame()) {
@@ -812,7 +817,7 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
         frame_tree_node->unique_name(), item_sequence_number,
         document_sequence_number, site_instance,
         std::move(source_site_instance), url, referrer, redirect_chain,
-        page_state, method, post_id);
+        page_state, method, post_id, is_srcdoc);
     return;
   }
 
@@ -840,7 +845,7 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
       child->frame_entry->UpdateEntry(
           unique_name, item_sequence_number, document_sequence_number,
           site_instance, std::move(source_site_instance), url, referrer,
-          redirect_chain, page_state, method, post_id);
+          redirect_chain, page_state, method, post_id, is_srcdoc);
       return;
     }
   }
@@ -851,7 +856,7 @@ void NavigationEntryImpl::AddOrUpdateFrameEntry(
   FrameNavigationEntry* frame_entry = new FrameNavigationEntry(
       unique_name, item_sequence_number, document_sequence_number,
       site_instance, std::move(source_site_instance), url, referrer, method,
-      post_id);
+      post_id, is_srcdoc);
   frame_entry->SetPageState(page_state);
   frame_entry->set_redirect_chain(redirect_chain);
   parent_node->children.push_back(