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 d21586b5d2d5044da08423bf4d7498a538d924d3..9ddf53cd59b473bb544d8d49ce0160b9d168b907 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"
@@ -1025,6 +1026,37 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, MAYBE_WebContentsHasFocus) {
       GetRenderWidgetHostView()->HasFocus());
 }
 
+class PlatformAppPrintBrowserTest : public PlatformAppBrowserTest {
+ public:
+  PlatformAppPrintBrowserTest() {}
+
+#if !defined(GOOGLE_CHROME_BUILD)

[Vitaly Buka (NO REVIEWS), 2013/08/28 01:20:26]

ifdef could be removed

[dharcourt, 2013/08/28 23:23:57]

Done.

+  // Ensures print tests use the print preview panel even for non-Chrome
+  // Chromium builds (Chrome branded builds always use this panel).
+  virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE {
+    command_line->AppendSwitch(switches::kEnablePrintPreview);
+    PlatformAppBrowserTest::SetUpCommandLine(command_line);
+  }
+#endif
+};
+
+// Currently this test doesn't work on OS X and only works if the PDF preview
+// plug-in is available. This plug-in will only be available in Chrome release
+// builds or if it has been manually copied from a Chrome release build. To run
+// this test when the plug-in has been manually copied, manually comment out the
+// GOOGLE_CHROME_BUILD part of the next line.
+#if defined(OS_MACOSX) || !defined(GOOGLE_CHROME_BUILD)
+#define MAYBE_WindowDotPrintWorks DISABLED_WindowDotPrintWorks
+#else
+#define MAYBE_WindowDotPrintWorks WindowDotPrintWorks
+#endif
+
+IN_PROC_BROWSER_TEST_F(PlatformAppPrintBrowserTest, MAYBE_WindowDotPrintWorks) {
+  PrintPreviewUI::SetAutoCancelForTesting(true);
+  ASSERT_TRUE(RunPlatformAppTest("platform_apps/print_api")) << message_;

[Vitaly Buka (NO REVIEWS), 2013/08/28 01:20:26]

without auto close, where exactly tests timeouts? inside of RunPlatformAppTest
or after

[dharcourt, 2013/08/28 23:23:57]

Inside RunPlatformAppTest, which never returns if the print panel is up.

FWIW, the timeouts were not occurring with the initial version of this change
list because the test JavaScript was explicitly calling chrome.test.notifyPass()
in that version, and that worked around the issue. Unfortunately
chrome.test.notifyPass() is not designed to be called this way and that version
of the test was susceptible to false negatives. Fixing that brought up the
timeout issue.

+  PrintPreviewUI::SetAutoCancelForTesting(false);

[Vitaly Buka (NO REVIEWS), 2013/08/28 01:20:26]

Probably you can avoid static methods using if you find UI using code:

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

[dharcourt, 2013/08/28 23:23:57]

Unfortunately I don't think I can use the same method here because the print
preview dialog gets created by JavaScript in the test app called by
RunPlatformAppTest() and so it doesn't exist at the time I want to set it to
auto-cancel. Am I missing something?

I've tried an alternative that uses FRIEND_TEST_ALL_PREFIXES() and private
static methods... is that any better, was the previous version better, or is
there another better way to do this?

+}
+
 
 #if defined(OS_CHROMEOS)