Don't attempt playback if not possible

chrome/browser/media/encrypted_media_browsertest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/windows_version.h"
 #include "chrome/browser/media/media_browsertest.h"
@@ skipping 398 matching lines @@
                           const std::string& media_type) {
     RunSimpleEncryptedMediaTest(encrypted_media,
                                 media_type,
                                 CurrentKeySystem(),
                                 CurrentSourceType(),
                                 CurrentEmeVersion());
   }
 
   void TestMultiplePlayback(const std::string& encrypted_media,
                             const std::string& media_type) {
+    // TestSimplePlayback() checks for KEY_ERROR if playback is not possible.

[ddorwin, 2015/03/16 19:17:47]

Instead, I would follow the pattern at line 596.

[jrummell, 2015/03/16 20:13:06]

Done.

+    // Since this just runs playback twice, don't waste time if playback not
+    // possible.
+    if (!IsPlayBackPossible(CurrentKeySystem()))
+      return;
+
     RunEncryptedMediaTest(kDefaultEmePlayer, encrypted_media, media_type,
                           CurrentKeySystem(), CurrentSourceType(),
                           CurrentEmeVersion(), kNoSessionToLoad, false,
                           PlayTwice::YES, kEnded);
   }
 
   void RunInvalidResponseTest() {
     RunEncryptedMediaTest(kDefaultEmePlayer, "bear-320x240-av_enc-av.webm",
                           kWebMAudioVideo, CurrentKeySystem(),
                           CurrentSourceType(), CurrentEmeVersion(),
@@ skipping 280 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(ECKPrefixedEncryptedMediaTest, LoadLoadableSession) {
   TestPlaybackCase(kLoadableSession, kEnded);
 }
 
 IN_PROC_BROWSER_TEST_F(ECKPrefixedEncryptedMediaTest, LoadUnknownSession) {
   // TODO(xhwang): Add a specific error for this failure, e.g. kSessionNotFound.
   TestPlaybackCase(kUnknownSession, kEmeKeyError);
 }
 #endif  // defined(ENABLE_PEPPER_CDMS)