Change the flow for UI mirroring tests to start mirroing first then play the video. Replace WaitUnt…

chrome/test/media_router/media_router_e2e_ui_browsertest.cc

Index: chrome/test/media_router/media_router_e2e_ui_browsertest.cc
diff --git a/chrome/test/media_router/media_router_e2e_ui_browsertest.cc b/chrome/test/media_router/media_router_e2e_ui_browsertest.cc
index b689266a361777faef61dddd67f63670762dc48c..463d6bc46d43b0ec90008b9edca4e86cacfda1e9 100644
--- a/chrome/test/media_router/media_router_e2e_ui_browsertest.cc
+++ b/chrome/test/media_router/media_router_e2e_ui_browsertest.cc
@@ -11,36 +11,40 @@
 namespace media_router {
 
 IN_PROC_BROWSER_TEST_F(MediaRouterE2EBrowserTest, MANUAL_MirrorHTML5Video) {
-  OpenMediaPage();
   content::WebContents* web_contents =
-        browser()->tab_strip_model()->GetActiveWebContents();
+      browser()->tab_strip_model()->GetActiveWebContents();
 
-  // Play the video on loop.
-  std::string script = "document.getElementsByTagName('video')[0].loop=true;";
-  ExecuteScript(web_contents, script);
-  // Wait for 5s to the video is playing smoothly.
-  Wait(base::TimeDelta::FromSeconds(5));
   content::WebContents* dialog_contents = OpenMRDialog(web_contents);
-  // Wait for 10s to make sure the dialog finishes rendering.
-  Wait(base::TimeDelta::FromSeconds(10));
   ASSERT_TRUE(dialog_contents);
+  // Wait for 2s to make sure the dialog finishes rendering.

[imcheng, 2017/01/24 20:03:31]

nit: blank line before comments here and below.

[cliffordcheng1, 2017/01/24 23:13:18]

Done.

+  Wait(base::TimeDelta::FromSeconds(2));

[imcheng, 2017/01/24 20:03:31]

Can you use WaitUntilDialogFullyLoaded() here and below? Prefer explicit
conditional checks vs. waiting for a fixed amount of time.

[cliffordcheng1, 2017/01/24 23:13:18]

Done.

   WaitUntilSinkDiscoveredOnUI();
   ChooseSink(web_contents, receiver());
-  WaitUntilRouteCreated();
-
   // Mirror tab for 10s.
   Wait(base::TimeDelta::FromSeconds(10));
 
+  OpenMRDialog(web_contents);
+  // Wait for 2s to make sure the dialog finishes rendering.
+  Wait(base::TimeDelta::FromSeconds(2));
+  // Check the mirroring session has started successfully.
+  ASSERT_TRUE(!GetRouteId(receiver()).empty());
+
+  OpenMediaPage();
+  // Play the video on loop.
+  std::string script = "document.getElementsByTagName('video')[0].loop=true;";
+  ExecuteScript(web_contents, script);
+  // Wait for 5s to the video is playing smoothly.
+  Wait(base::TimeDelta::FromSeconds(5));
   // Go to full screen.
   script = "document.getElementsByTagName('video')[0]."
       "webkitRequestFullScreen();";
   ExecuteScript(web_contents, script);
   // Wait for 5s to the video is playing smoothly in full screen.
   Wait(base::TimeDelta::FromSeconds(5));
-  OpenMRDialog(web_contents);
-  // Wait for 5s to make sure the dialog finishes rendering.
-  Wait(base::TimeDelta::FromSeconds(5));
 
+  OpenMRDialog(web_contents);
+  // Wait for 2s to make sure the dialog finishes rendering.
+  Wait(base::TimeDelta::FromSeconds(2));
   // Check the mirroring session is still live.
   ASSERT_TRUE(!GetRouteId(receiver()).empty());
   Wait(base::TimeDelta::FromSeconds(20));