NOT YET READY: Improve granularity of window namespaces in Blink.

third_party/WebKit/Source/core/page/Page.cpp

Index: third_party/WebKit/Source/core/page/Page.cpp
diff --git a/third_party/WebKit/Source/core/page/Page.cpp b/third_party/WebKit/Source/core/page/Page.cpp
index 4a083020409fba2b7999b1c52cfb1bf00e5c6589..1a12f7a059098223958b1aa4c38303d29dd1cf55 100644
--- a/third_party/WebKit/Source/core/page/Page.cpp
+++ b/third_party/WebKit/Source/core/page/Page.cpp
@@ -78,6 +78,16 @@ Page::PageSet& Page::OrdinaryPages() {
   return pages;
 }
 
+HeapVector<Member<Page>> Page::RelatedPages() {
+  HeapVector<Member<Page>> result;
+  Page* ptr = this->next_related_page_;
+  while (ptr != this) {
+    result.push_back(ptr);
+    ptr = ptr->next_related_page_;
+  }
+  return result;
+}
+
 float DeviceScaleFactorDeprecated(LocalFrame* frame) {
   if (!frame)
     return 1;
@@ -87,8 +97,19 @@ float DeviceScaleFactorDeprecated(LocalFrame* frame) {
   return page->DeviceScaleFactorDeprecated();
 }
 
-Page* Page::CreateOrdinary(PageClients& page_clients) {
+Page* Page::CreateOrdinary(PageClients& page_clients, Page* opener) {
   Page* page = Create(page_clients);
+
+  if (opener) {
+    // Before: ... -> opener -> next -> ...
+    // After: ... -> opener -> page -> next -> ...
+    Page* next = opener->next_related_page_;
+    opener->next_related_page_ = page;
+    page->prev_related_page_ = opener;
+    page->next_related_page_ = next;
+    next->prev_related_page_ = page;
+  }
+
   OrdinaryPages().insert(page);
   if (ScopedPageSuspender::IsActive())
     page->SetSuspended(true);
@@ -130,7 +151,9 @@ Page::Page(PageClients& page_clients)
       device_scale_factor_(1),
       visibility_state_(kPageVisibilityStateVisible),
       is_cursor_visible_(true),
-      subframe_count_(0) {
+      subframe_count_(0),
+      next_related_page_(this),
+      prev_related_page_(this) {
   DCHECK(editor_client_);
 
   DCHECK(!AllPages().Contains(this));
@@ -639,6 +662,8 @@ DEFINE_TRACE(Page) {
   visitor->Trace(plugin_data_);
   visitor->Trace(validation_message_client_);
   visitor->Trace(use_counter_);
+  visitor->Trace(next_related_page_);
+  visitor->Trace(prev_related_page_);
   Supplementable<Page>::Trace(visitor);
   PageVisibilityNotifier::Trace(visitor);
 }
@@ -667,6 +692,18 @@ void Page::WillBeDestroyed() {
   AllPages().erase(this);
   OrdinaryPages().erase(this);
 
+  {
+    // Before: ... -> prev -> this -> next -> ...
+    // After: ... -> prev -> next -> ...
+    // (this is ok even if |this| is the only element on the list).
+    Page* prev = this->prev_related_page_;
+    Page* next = this->next_related_page_;
+    next->prev_related_page_ = prev;
+    prev->next_related_page_ = next;
+    this->prev_related_page_ = nullptr;
+    this->next_related_page_ = nullptr;
+  }
+
   if (scrolling_coordinator_)
     scrolling_coordinator_->WillBeDestroyed();