[Session restore] Expose lazy mode and fix browser tests.

chrome/browser/sessions/better_session_restore_browsertest.cc

Index: chrome/browser/sessions/better_session_restore_browsertest.cc
diff --git a/chrome/browser/sessions/better_session_restore_browsertest.cc b/chrome/browser/sessions/better_session_restore_browsertest.cc
index b6c902602705912c394a4dfe3bd2a2f7ec7deb59..c611a04e2fe3aa2b8bd7cd299116904d2ec6012b 100644
--- a/chrome/browser/sessions/better_session_restore_browsertest.cc
+++ b/chrome/browser/sessions/better_session_restore_browsertest.cc
@@ -214,6 +214,12 @@ class BetterSessionRestoreTest : public InProcessBrowserTest {
   }
 
   void CheckReloadedPageNotRestored() {
+    // If only active tabs are loaded, force loading of the tab.
+    if (SessionRestore::IsLoadingActiveTabsOnly()) {
+      content::WebContents* web_contents =
+          browser()->tab_strip_model()->GetWebContentsAt(0);

[sky, 2015/04/16 15:40:10]

Is there only ever one webcontents that isn't loading? Seems better to invoke
LoadIfNecessary on all webcontents.

[Georges Khalil, 2015/04/16 18:10:18]

Yes, this only has one page. If calls CheckTitle which waits
for the title of that single page to change (line 230).

That being said, the change was simple to loop the webcontents
and makes the code more futureproof.

Done.

+      web_contents->GetController().LoadIfNecessary();
+    }
     CheckReloadedPageNotRestored(browser());
   }