Implement modal permission prompts for media permissions on Android.

chrome/browser/media/webrtc/permission_bubble_media_access_handler.cc

Index: chrome/browser/media/webrtc/permission_bubble_media_access_handler.cc
diff --git a/chrome/browser/media/webrtc/permission_bubble_media_access_handler.cc b/chrome/browser/media/webrtc/permission_bubble_media_access_handler.cc
index 5b1855353838f0e904929e9e7048f3e0c30fc56b..6437567a19fe74cfc7544072ac7b3e2aab216e63 100644
--- a/chrome/browser/media/webrtc/permission_bubble_media_access_handler.cc
+++ b/chrome/browser/media/webrtc/permission_bubble_media_access_handler.cc
@@ -27,6 +27,7 @@
 #include "chrome/browser/android/chrome_feature_list.h"
 #include "chrome/browser/media/webrtc/media_stream_infobar_delegate_android.h"
 #include "chrome/browser/media/webrtc/screen_capture_infobar_delegate_android.h"
+#include "chrome/browser/permissions/permission_dialog_delegate.h"
 #include "chrome/browser/permissions/permission_update_infobar_delegate_android.h"
 #else
 #include "chrome/browser/permissions/permission_request_manager.h"
@@ -191,8 +192,13 @@ void PermissionBubbleMediaAccessHandler::ProcessQueuedAccessRequest(
   }
 
 #if BUILDFLAG(ANDROID_JAVA_UI)
-  MediaStreamInfoBarDelegateAndroid::Create(web_contents,
-                                            std::move(controller));
+  if (PermissionDialogDelegate::ShouldShowDialog(request.user_gesture)) {
+    PermissionDialogDelegate::CreateMediaStreamDialog(web_contents,

[raymes, 2016/11/02 08:09:04]

Hmm - there seems to be some logic in MediaStreamInfoBarDelegateAndroid::Create
that may be important:

if (!infobar_service) {
    // Deny the request if there is no place to show the infobar, e.g. when
    // the request comes from a background extension page.
    controller->Cancelled();
    return false;
  }

We may need to keep this logic?

[dominickn, 2016/11/03 00:34:09]

I don't think it's possible for anything except a real tab to request this
permission on Android (e.g. there are no extensions).

+                                                      std::move(controller));
+  } else {
+    MediaStreamInfoBarDelegateAndroid::Create(web_contents,
+                                              std::move(controller));
+  }
 #else
   PermissionRequestManager* permission_request_manager =
       PermissionRequestManager::FromWebContents(web_contents);