Don't share renderers between unrelated tabs on Android.

content/browser/site_instance_impl_unittest.cc

Index: content/browser/site_instance_impl_unittest.cc
diff --git a/content/browser/site_instance_impl_unittest.cc b/content/browser/site_instance_impl_unittest.cc
index 646f4d079577593e5fdc0be8d9a10c8dc1696a19..fe76b484fc460c8b43a645026f77e40c876c37f3 100644
--- a/content/browser/site_instance_impl_unittest.cc
+++ b/content/browser/site_instance_impl_unittest.cc
@@ -562,6 +562,13 @@ TEST_F(SiteInstanceTest, ProcessSharingByType) {
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kSitePerProcess))
     return;
 
+  // On Android by default the number of renderer hosts is unlimited and process
+  // sharing doesn't happen. We set the override so that the test can run
+  // everywhere.
+  size_t old_renderer_process_limit =
+      RenderProcessHost::GetMaxRendererProcessCount();
+  RenderProcessHost::SetMaxRendererProcessCount(kMaxRendererProcessCount);
+
   ChildProcessSecurityPolicyImpl* policy =
       ChildProcessSecurityPolicyImpl::GetInstance();
 
@@ -607,6 +614,9 @@ TEST_F(SiteInstanceTest, ProcessSharingByType) {
   }
 
   DrainMessageLoops();
+
+  // Disable the process limit override.
+  RenderProcessHost::SetMaxRendererProcessCount(0);
 }
 
 // Test to ensure that HasWrongProcessForURL behaves properly for different