Add performance.now() to the d8 shell.

test/mjsunit/d8-performance-now.js

Index: test/mjsunit/d8-performance-now.js
diff --git a/test/cctest/test-cpu-ia32.cc b/test/mjsunit/d8-performance-now.js
similarity index 82%
copy from test/cctest/test-cpu-ia32.cc
copy to test/mjsunit/d8-performance-now.js
index 245450bf92b595e417a53edff09a5849d74dd135..090ccefd8e9c62d27afc9a04ef0d7709d2d3789e 100644
--- a/test/cctest/test-cpu-ia32.cc
+++ b/test/mjsunit/d8-performance-now.js
@@ -25,16 +25,15 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#include "v8.h"
+// Test the window.performance.now() function of d8.  This test only makes
+// sense with d8.

[Hannes Payer (out of office), 2013/10/23 09:59:51]

Can we revive the old test/mjsunit/timer.js here to test performance now
granularity and monotonicity?

[Benedikt Meurer, 2013/10/24 09:00:49]

Done.

 
-#include "cctest.h"
-#include "cpu.h"
-
-using namespace v8::internal;
-
-
-TEST(RequiredFeaturesX64) {
-  // Test for the features required by every x86 CPU in compat/legacy mode.
-  CPU cpu;
-  CHECK(cpu.has_sahf());
+var init = window.performance.now();
+var prev = init;
+var date = Date.now();
+while (Date.now() <= date + 15) {
+  var next = window.performance.now();
+  assertTrue(next >= prev);
+  prev = next;
 }
+assertTrue(window.performance.now() > init);