Update page_cycler to use sessionStorage.

Patch from Ahmad Sharif <asharif@chromium.org>.

This was landed previously as r56932 and reverted in
r57445.  Previous landing showed some flakiness/failures
in the DOM automation framework.  Relanding to verify
if this is fixed or still broken.

BUG=53491
TEST=page cyclers stay green

Review URL: http://codereview.chromium.org/5955002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@69492 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/page_cycler/page_cycler_test.cc

@@ -163,6 +163,7 @@ class PageCyclerTest : public UIPerfTest {
   PageCyclerTest()
       : print_times_only_(false) {
     show_window_ = true;
+    dom_automation_enabled_ = true;
 
     const CommandLine& parsed_command_line = *CommandLine::ForCurrentProcess();
     num_test_iterations_ = kTestIterations;
@@ -246,6 +247,14 @@ class PageCyclerTest : public UIPerfTest {
     pages->assign(UTF8ToWide(cookie));
     ASSERT_FALSE(pages->empty());
     ASSERT_TRUE(tab->GetCookieByName(test_url, "__pc_timings", &cookie));
+
+    std::wstring wcookie;
+    ASSERT_TRUE(tab->ExecuteAndExtractString(L"",
+          L"window.domAutomationController.send("
+          L"JSON.stringify(__get_timings()));",
+          &wcookie));
+    cookie = base::SysWideToNativeMB(wcookie);
+
     timings->assign(cookie);
     ASSERT_FALSE(timings->empty());
   }

tools/page_cycler/common/head.js

@@ -26,10 +26,20 @@ function __pages() {  // fetch lazily
   return this.data;
 }
 function __get_timings() {
-  return __get_cookie("__pc_timings");
+  if (sessionStorage == null)
+    return __get_cookie("__pc_timings");
+  else {
+    if (sessionStorage.getItem("__pc_timings") == null)
+      return "";
+    else
+      return sessionStorage["__pc_timings"];
+  }
 }
 function __set_timings(timings) {
-  document.cookie = "__pc_timings=" + timings + "; path=/";
+  if (sessionStorage == null)
+    document.cookie = "__pc_timings=" + timings + "; path=/";
+  else
+    sessionStorage["__pc_timings"]=timings;
 }
 function __ontimeout() {
   var doc;