Implemented ForceMaximizeBrowserWindowOnFirstRun policy, added unit test and browser test.

ash/test/test_shell_delegate.cc

Index: ash/test/test_shell_delegate.cc
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index 9b11604bbad2aa499fbc3d1044b4ab0cf7d3efef..ee6fd44a06c28c7d52be65d43248b76dd3d5a52e 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -82,6 +82,7 @@ class MediaDelegateImpl : public MediaDelegate {
 TestShellDelegate::TestShellDelegate()
     : num_exit_requests_(0),
       multi_profiles_enabled_(false),
+      force_maximize_on_first_run_(false),
       test_session_state_delegate_(NULL) {
 }
 
@@ -108,6 +109,10 @@ bool TestShellDelegate::IsMultiAccountEnabled() const {
   return false;
 }
 
+bool TestShellDelegate::IsForceMaximizeOnFirstRun() const {
+  return force_maximize_on_first_run_;
+}
+
 void TestShellDelegate::PreInit() {
 }