Reland "media: MediaBrowserTest not watching for plugin crash"

This reverts commit 56d3597e and
relands the original CL.

Reason for revert: The failure (revert reason) doesn't seem to be
caused by this CL.

Original change's description:
> media: MediaBrowserTest not watching for plugin crash
>
> Now the CDM is not running in a plugin, there's no need for
> MediaBrowserTest to watch for plugin crash.

Bug: 772160
Change-Id: I387abcd37e85b703e2d0d1bf67be1f82dd68bf68
Reviewed-on: https://chromium-review.googlesource.com/1174852Reviewed-by: John Rummell <jrummell@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583304}

chrome/browser/media/encrypted_media_browsertest.cc

@@ -727,7 +727,6 @@ IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, InitializeCDMFail) {
 // be closed.
 // Flaky: crbug.com/832800
 IN_PROC_BROWSER_TEST_P(ECKEncryptedMediaTest, DISABLED_CDMCrashDuringDecode) {
-  IgnorePluginCrash();
   TestNonPlaybackCases(kExternalClearKeyCrashKeySystem,
                        kEmeSessionClosedAndError);
 }

chrome/browser/media/media_browsertest.cc

@@ -17,7 +17,7 @@
 #include "media/base/test_data_util.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 
-MediaBrowserTest::MediaBrowserTest() : ignore_plugin_crash_(false) {}
+MediaBrowserTest::MediaBrowserTest() {}
 
 MediaBrowserTest::~MediaBrowserTest() {}
 
@@ -47,8 +47,7 @@ std::string MediaBrowserTest::RunTest(const GURL& gurl,
                                       const std::string& expected_title) {
   DVLOG(0) << base::TimeFormatTimeOfDayWithMilliseconds(base::Time::Now())
            << " Running test URL: " << gurl;
-  // Observe the web contents for plugin crashes.
-  Observe(browser()->tab_strip_model()->GetActiveWebContents());
+
   content::TitleWatcher title_watcher(
       browser()->tab_strip_model()->GetActiveWebContents(),
       base::ASCIIToUTF16(expected_title));
@@ -63,15 +62,3 @@ void MediaBrowserTest::AddWaitForTitles(content::TitleWatcher* title_watcher) {
   title_watcher->AlsoWaitForTitle(base::ASCIIToUTF16(media::kError));
   title_watcher->AlsoWaitForTitle(base::ASCIIToUTF16(media::kFailed));
 }
-
-void MediaBrowserTest::PluginCrashed(const base::FilePath& plugin_path,
-                                     base::ProcessId plugin_pid) {
-  DVLOG(0) << "Plugin crashed: " << plugin_path.value();
-  if (ignore_plugin_crash_)
-    return;
-  ADD_FAILURE() << "Failing test due to plugin crash.";
-}
-
-void MediaBrowserTest::IgnorePluginCrash() {
-  ignore_plugin_crash_ = true;
-}

chrome/browser/media/media_browsertest.h

@@ -8,7 +8,6 @@
 #include <string>
 
 #include "chrome/test/base/in_process_browser_test.h"
-#include "content/public/browser/web_contents_observer.h"
 #include "media/base/test_data_util.h"
 
 namespace content {
@@ -18,8 +17,7 @@ class TitleWatcher;
 // Class used to automate running media related browser tests. The functions
 // assume that media files are located under media/ folder known to the test
 // http server.
-class MediaBrowserTest : public InProcessBrowserTest,
-                         public content::WebContentsObserver {
+class MediaBrowserTest : public InProcessBrowserTest {
  protected:
   MediaBrowserTest();
   ~MediaBrowserTest() override;
@@ -38,17 +36,6 @@ class MediaBrowserTest : public InProcessBrowserTest,
   std::string RunTest(const GURL& gurl, const std::string& expected);
 
   virtual void AddWaitForTitles(content::TitleWatcher* title_watcher);
-
-  // Fails test and sets document title to kPluginCrashed when a plugin crashes.
-  // If IgnorePluginCrash(true) is called then plugin crash is ignored.
-  void PluginCrashed(const base::FilePath& plugin_path,
-                     base::ProcessId plugin_pid) override;
-
-  // When called, the test will ignore any plugin crashes and not fail the test.
-  void IgnorePluginCrash();
-
- private:
-  bool ignore_plugin_crash_;
 };
 
 #endif  // CHROME_BROWSER_MEDIA_MEDIA_BROWSERTEST_H_