Added basic browser test for window.print() from Chrome apps.

chrome/browser/apps/app_browsertest.cc

Index: chrome/browser/apps/app_browsertest.cc
diff --git a/chrome/browser/apps/app_browsertest.cc b/chrome/browser/apps/app_browsertest.cc
index ec4a1a5858531adbf50d70135e75ee34cc8338f1..951fd093297f88b534d1dbf3ffe5be655e2e1ab0 100644
--- a/chrome/browser/apps/app_browsertest.cc
+++ b/chrome/browser/apps/app_browsertest.cc
@@ -31,6 +31,7 @@
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/extensions/application_launch.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/webui/print_preview/print_preview_ui.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/api/app_runtime.h"
 #include "chrome/common/pref_names.h"
@@ -1036,6 +1037,24 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, MAYBE_WebContentsHasFocus) {
       GetRenderWidgetHostView()->HasFocus());
 }
 
+// Currently this test only works if the PDF preview plug-in is available. This
+// will only happen in Chrome release builds or if the plug-in has been manually
+// copied from a Chrome release build. In the former case, this test will run
+// automatically. In the later case, it can be run manually by commenting out
+// the next three lines and the corresponding #endif and then running
+// browser_tests with a --enable-print-preview flag.
+#if !defined(GOOGLE_CHROME_BUILD)
+#define MAYBE_WindowDotPrintWorks DISABLED_WindowDotPrintWorks
+#else
+#define MAYBE_WindowDotPrintWorks WindowDotPrintWorks
+#endif
+
+IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, MAYBE_WindowDotPrintWorks) {
+  PrintPreviewUI::SetAutoCancelForTesting(true);
+  ASSERT_TRUE(RunPlatformAppTest("platform_apps/print_api")) << message_;
+  PrintPreviewUI::SetAutoCancelForTesting(false);
+}
+
 
 #if defined(OS_CHROMEOS)