Bug 1306266 - test for print preview using the right tab, r=mconley

MozReview-Commit-ID: LLFmpPWwc5d

UltraBlame original commit: 38485e7430ba0a2107ddbb617e027ac00a688813

browser/base/content/test/tabs/browser.ini

@@ -1,2 +1,4 @@
 [browser_tabSpinnerProbe.js]
 skip-if = !e10s # Tab spinner is e10s only.
+[browser_tabSwitchPrintPreview.js]
+skip-if = os == 'mac'

browser/base/content/test/tabs/browser_tabSwitchPrintPreview.js

@@ -0,0 +1,23 @@
+const kURL1 = "data:text/html,Should I stay or should I go?";
+const kURL2 = "data:text/html,I shouldn't be here!";
+
+
+
+
+
+add_task(function* () {
+  yield BrowserTestUtils.withNewTab(kURL1, function* (browser) {
+    let tab = gBrowser.addTab(kURL2);
+    document.getElementById("cmd_printPreview").doCommand();
+    gBrowser.selectedTab = tab;
+    yield BrowserTestUtils.waitForCondition(() => gInPrintPreviewMode, "should be in print preview mode");
+    isnot(gBrowser.selectedTab, tab, "Selected tab should not be the tab we added");
+    is(gBrowser.selectedTab, PrintPreviewListener._printPreviewTab, "Selected tab should be the print preview tab");
+    gBrowser.selectedTab = tab;
+    isnot(gBrowser.selectedTab, tab, "Selected tab should still not be the tab we added");
+    is(gBrowser.selectedTab, PrintPreviewListener._printPreviewTab, "Selected tab should still be the print preview tab");
+    PrintUtils.exitPrintPreview();
+    yield BrowserTestUtils.waitForCondition(() => !gInPrintPreviewMode, "should be in print preview mode");
+    yield BrowserTestUtils.removeTab(tab);
+  });
+});