Fix process reuse for dedicated processes when over process limit.

content/browser/renderer_host/render_process_host_unittest.cc

 // Copyright 2013 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 <stddef.h>
 
 #include <limits>
 #include <memory>
 #include <vector>
 
@@ skipping 133 matching lines @@
     subframe->SendRendererInitiatedNavigationRequest(kUrl1, false);
     subframe->PrepareForCommit();
     subframe->SendNavigateWithParams(&params);
   }
   site_instance = SiteInstanceImpl::CreateForURL(browser_context(), kUrl1);
   site_instance->set_process_reuse_policy(
       SiteInstanceImpl::ProcessReusePolicy::REUSE_PENDING_OR_COMMITTED_SITE);
   EXPECT_EQ(subframe->GetProcess(), site_instance->GetProcess());
 }
 
+// Check that only new processes that haven't yet hosted any web content are
+// allowed to be reused to host a site requiring a dedicated process.
+TEST_F(RenderProcessHostUnitTest, CanBecomeDedicatedProcess) {
+  const GURL kUrl1("http://foo.com");
+
+  // A process for a SiteInstance that has no site should be able to host any
+  // site that requires a dedicated process.
+  EXPECT_FALSE(main_test_rfh()->GetSiteInstance()->HasSite());
+  EXPECT_TRUE(main_test_rfh()->GetProcess()->CanBecomeDedicatedProcess());
+  {
+    scoped_refptr<SiteInstanceImpl> site_instance =
+        SiteInstanceImpl::Create(browser_context());
+    EXPECT_FALSE(site_instance->HasSite());
+    EXPECT_TRUE(site_instance->GetProcess()->CanBecomeDedicatedProcess());
+  }
+
+  // Navigation should mark the process as unable to become a dedicated process
+  // for arbitrary sites.
+  NavigateAndCommit(kUrl1);
+  EXPECT_FALSE(main_test_rfh()->GetProcess()->CanBecomeDedicatedProcess());
+
+  // A process for a SiteInstance that has been created for a particular site
+  // is considered unsuitable to host arbitrary sites requiring a dedicated
+  // process from the point it is created via GetProcess().
+  {
+    scoped_refptr<SiteInstanceImpl> site_instance =
+        SiteInstanceImpl::CreateForURL(browser_context(), kUrl1);
+    EXPECT_FALSE(site_instance->GetProcess()->CanBecomeDedicatedProcess());

[Charlie Reis, 2017/06/12 23:08:17]

What would happen if kUrl1 was a site requiring a dedicated process?  The name
is a bit odd here, since GetProcess() would be a dedicated process, but
CanBecomeDedicatedProcess() would presumably return false.

(Maybe the later suggestion about the name might help.)

[alexmos, 2017/06/14 22:39:05]

Yes, I renamed the method and reworded the comment to avoid this confusion.

+  }
+}
+
 // Tests that RenderProcessHost will not consider reusing a process that has
 // committed an error page.
 TEST_F(RenderProcessHostUnitTest, DoNotReuseError) {
   const GURL kUrl1("http://foo.com");
   const GURL kUrl2("http://bar.com");
 
   // At first, trying to get a RenderProcessHost with the
   // REUSE_PENDING_OR_COMMITTED_SITE policy should return a new process.
   scoped_refptr<SiteInstanceImpl> site_instance =
       SiteInstanceImpl::CreateForURL(browser_context(), kUrl1);
@@ skipping 308 matching lines @@
   // main RFH, as it was registered with the regular site URL when it committed.
   main_test_rfh()->PrepareForCommit();
   main_test_rfh()->SendNavigate(0, true, kUrl);
   site_instance = SiteInstanceImpl::CreateForURL(browser_context(), kUrl);
   site_instance->set_process_reuse_policy(
       SiteInstanceImpl::ProcessReusePolicy::REUSE_PENDING_OR_COMMITTED_SITE);
   EXPECT_EQ(main_test_rfh()->GetProcess(), site_instance->GetProcess());
 }
 
 }  // namespace content