Added switch for bypassing protected media identifier permission

chrome/browser/media/protected_media_identifier_permission_context.cc

Index: chrome/browser/media/protected_media_identifier_permission_context.cc
diff --git a/chrome/browser/media/protected_media_identifier_permission_context.cc b/chrome/browser/media/protected_media_identifier_permission_context.cc
index 50c2dc51ec53a1f4269eff81c038c44fc6eb40bc..ae36ffd4a1a10340eef2535fe1d956b3d5643fcd 100644
--- a/chrome/browser/media/protected_media_identifier_permission_context.cc
+++ b/chrome/browser/media/protected_media_identifier_permission_context.cc
@@ -15,7 +15,9 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
-#if defined(OS_CHROMEOS)
+#if defined(OS_ANDROID)
+#include "media/base/media_switches.h"
+#elif defined(OS_CHROMEOS)
 #include <utility>
 
 #include "chrome/browser/chromeos/attestation/platform_verification_dialog.h"
@@ -25,7 +27,7 @@
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/user_prefs/user_prefs.h"
 #include "ui/views/widget/widget.h"
-#elif !defined(OS_ANDROID)
+#else
 #error This file currently only supports Chrome OS and Android.
 #endif
 
@@ -101,6 +103,21 @@ ProtectedMediaIdentifierPermissionContext::GetPermissionStatusInternal(
          content_setting == CONTENT_SETTING_BLOCK ||
          content_setting == CONTENT_SETTING_ASK);
 
+  #if defined(OS_ANDROID)

[Joey Parrish, 2017/04/17 19:45:18]

I am of the opinion that this could be useful in other places than Android. 
ChromeOS, for example, may start prompting in similar scenarios in future, and
it would be helpful if we didn't have to patch Chromium again when that happens.

[Vaage, 2017/04/19 16:55:47]

Done.

+  const bool isLocal = requesting_origin.host() == "localhost" &&
+                       embedding_origin.host() == "localhost";

[Joey Parrish, 2017/04/17 19:45:18]

I found this, for context:
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/WZsI_gFftmc

Based on that, I think checking both here is reasonable.

However, I think it would be better if host() did not have to be literally the
string "localhost".  "127.0.0.1", "localhost.localdomain", etc, should also be
allowed (ideally).

I hit cs.chromium.org and searched for "localhost" and "127.0.0.1", which led me
to this utility:

https://cs.chromium.org/chromium/src/net/base/url_util.cc?dr=CSs&l=350

[Vaage, 2017/04/19 16:55:47]

Done.

+
+  // For testing of protected content, always allow content from localhost
+  // if the switch has been set.
+  const bool allowLocalContent =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableInfobarForProtectedMediaIdentifierForLocalhost);
+
+  if (allowLocalContent && isLocal && content_setting == CONTENT_SETTING_ASK) {
+    content_setting = CONTENT_SETTING_ALLOW;
+  }
+  #endif
+
   return content_setting;
 }