Add a basic postMessage test for <webview> in a new test suite.

chrome/browser/apps/guest_view/web_view_browsertest.cc

Index: chrome/browser/apps/guest_view/web_view_browsertest.cc
diff --git a/chrome/browser/apps/guest_view/web_view_browsertest.cc b/chrome/browser/apps/guest_view/web_view_browsertest.cc
index 27f24f6b5a83ace972b9cb47b963d014745424ff..a76b2e4d1405fa8b83232be69d6b080845cda15a 100644
--- a/chrome/browser/apps/guest_view/web_view_browsertest.cc
+++ b/chrome/browser/apps/guest_view/web_view_browsertest.cc
@@ -844,6 +844,10 @@ class WebViewTest : public extensions::PlatformAppBrowserTest {
   content::WebContents* embedder_web_contents_;
 };
 
+// Test suite that containts tests that are meant to run with and without
+// --site-per-process.
+class WebViewBasicTest : public extensions::PlatformAppBrowserTest {};

[lfg, 2015/05/21 22:49:25]

[optional] I don't like the BasicTest name, maybe WebViewCommonTest to show that
it's common between the two modes? Or maybe you could think of a better name :)

[lazyboy, 2015/05/21 23:31:05]

Renamed to WebViewCommonTest.

+
 class WebViewDPITest : public WebViewTest {
  protected:
   void SetUpCommandLine(base::CommandLine* command_line) override {
@@ -2718,3 +2722,9 @@ IN_PROC_BROWSER_TEST_F(WebViewTest, AllowTransparencyAndAllowScalingPropagate) {
   ASSERT_TRUE(guest->allow_transparency());
   ASSERT_TRUE(guest->allow_scaling());
 }
+
+IN_PROC_BROWSER_TEST_F(WebViewBasicTest, BasicPostMessage) {
+  ASSERT_TRUE(StartEmbeddedTestServer());  // For serving guest pages.
+  ASSERT_TRUE(RunPlatformAppTest("platform_apps/web_view/post_message/basic"))
+      << message_;
+}