Don't create separate SiteInstances for pages from the same domain and scheme...

chrome/browser/site_instance_unittest.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/navigation_entry.h"
 #include "chrome/browser/render_view_host.h"
 #include "chrome/browser/web_contents.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/test/testing_profile.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 184 matching lines @@
   EXPECT_TRUE(instance.get()->site().is_empty());
 
   instance.get()->SetSite(GURL("http://www.google.com/index.html"));
   EXPECT_EQ(GURL("http://google.com"), instance.get()->site());
 
   EXPECT_TRUE(instance->has_site());
 }
 
 // Test to ensure GetSiteForURL properly returns sites for URLs.
 TEST_F(SiteInstanceTest, GetSiteForURL) {
+  // Pages are irrelevant.
   GURL test_url = GURL("http://www.google.com/index.html");
   EXPECT_EQ(GURL("http://google.com"), SiteInstance::GetSiteForURL(test_url));
 
+  // Ports are irrlevant.
   test_url = GURL("https://www.google.com:8080");
-  EXPECT_EQ(GURL("https://google.com:8080"),
-            SiteInstance::GetSiteForURL(test_url));
+  EXPECT_EQ(GURL("https://google.com"), SiteInstance::GetSiteForURL(test_url));
 
+  // Javascript URLs have no site.
   test_url = GURL("javascript:foo();");
   EXPECT_EQ(GURL::EmptyGURL(), SiteInstance::GetSiteForURL(test_url));
 
   test_url = GURL("http://foo/a.html");
   EXPECT_EQ(GURL("http://foo"), SiteInstance::GetSiteForURL(test_url));
 
   test_url = GURL("file:///C:/Downloads/");
   EXPECT_EQ(GURL::EmptyGURL(), SiteInstance::GetSiteForURL(test_url));
 
   // TODO(creis): Do we want to special case file URLs to ensure they have
   // either no site or a special "file://" site?  We currently return
   // "file://home/" as the site, which seems broken.
   // test_url = GURL("file://home/");
   // EXPECT_EQ(GURL::EmptyGURL(), SiteInstance::GetSiteForURL(test_url));
 }
 
 // Test of distinguishing URLs from different sites.  Most of this logic is
 // tested in RegistryControlledDomainTest.  This test focuses on URLs with
 // different schemes or ports.
 TEST_F(SiteInstanceTest, IsSameWebSite) {
   GURL url_foo = GURL("http://foo/a.html");
   GURL url_foo2 = GURL("http://foo/b.html");
   GURL url_foo_https = GURL("https://foo/a.html");
   GURL url_foo_port = GURL("http://foo:8080/a.html");
   GURL url_javascript = GURL("javascript:alert(1);");
   GURL url_crash = GURL("about:crash");
   GURL url_hang = GURL("about:hang");
   GURL url_shorthang = GURL("about:shorthang");
 
+  // Same scheme and port -> same site.
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_foo, url_foo2));
+
+  // Different scheme -> different site.
   EXPECT_FALSE(SiteInstance::IsSameWebSite(url_foo, url_foo_https));
-  EXPECT_FALSE(SiteInstance::IsSameWebSite(url_foo, url_foo_port));
+
+  // Different port -> same site.
+  // (Changes to document.domain make renderer ignore the port.)
+  EXPECT_TRUE(SiteInstance::IsSameWebSite(url_foo, url_foo_port));
 
   // JavaScript links should be considered same site for anything.
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_javascript, url_foo));
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_javascript, url_foo_https));
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_javascript, url_foo_port));
 
   // The crash/hang URLs should also be treated as same site.  (Bug 1143809.)
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_crash, url_foo));
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_hang, url_foo));
   EXPECT_TRUE(SiteInstance::IsSameWebSite(url_shorthang, url_foo));
@@ skipping 122 matching lines @@
 
   // Should be able to see that we don't have SiteInstances.
   EXPECT_FALSE(browsing_instance->HasSiteInstance(
       GURL("https://www.google.com")));  // not visited before
   EXPECT_FALSE(browsing_instance3->HasSiteInstance(
       GURL("http://www.yahoo.com")));  // different BI, different profile
 
   // browsing_instances will be deleted when their SiteInstances are deleted
 }