Factor out the test web contents from the WebContents unit test so that it ca...

chrome/browser/tab_contents/site_instance.cc

Index: chrome/browser/tab_contents/site_instance.cc
===================================================================
--- chrome/browser/tab_contents/site_instance.cc	(revision 8331)
+++ chrome/browser/tab_contents/site_instance.cc	(working copy)
@@ -28,8 +28,14 @@
           browsing_instance_->profile());
 
     // Otherwise (or if that fails), create a new one.
-    if (!process)
-      process = new BrowserRenderProcessHost(browsing_instance_->profile());
+    if (!process) {
+      if (render_process_host_factory_) {
+        process = render_process_host_factory_->CreateRenderProcessHost(
+            browsing_instance_->profile());
+      } else {
+        process = new BrowserRenderProcessHost(browsing_instance_->profile());
+      }
+    }
 
     // Update our host ID, so all pages in this SiteInstance will use
     // the correct process.