Add JCEF browser (#6787)

We want to add this as an option for users who are experiencing problems
with the embedded DevTools window, e.g.
#6759. I'm not sure if
the JCEF browser will be better for cases that are causing problems in
the JxBrowser implementation, but I figure we want to start gathering
info on how JCEF performs anyway if we want to eventually move away from
JxBrowser and its file downloads.

@AlexV525 I've reorganized the management of multiple browsers and
content, something you introduced in
#6772. I pointed out one
spot where I'm not sure if my change will work as expected; if you have
a chance, please look over/test and let me know.

Author: helin24

flutter-idea/src/io/flutter/FlutterBundle.properties

@@ -213,6 +213,8 @@ settings.allow.tests.tooltip=The directory must be marked as a sources root, suc
 settings.font.packages=Font Packages
 settings.show.all.configs=Show all possible run configurations for apps or tests, even if a created configuration already exists
 settings.show.all.configs.tooltip=If there is a defined run configuration to watch a specific test and one to just run it, show both.
+settings.jcef.browser=Use JCEF browser to show embedded DevTools
+settings.jcef.browser.tooltip=JCEF is a browser included in IntelliJ that is an alternative to using JxBrowser for showing embedded DevTools.
 settings.enable.androi.gradle.sync.tooltip=Provides advanced editing capabilities for Java and Kotlin code. Uses Gradle to find Android libraries then links them into the Flutter project.
 settings.experiments=Experiments
 settings.editor=Editor

flutter-idea/src/io/flutter/FlutterUtils.java

@@ -36,11 +36,15 @@
 import com.intellij.util.PlatformUtils;
 import com.jetbrains.lang.dart.DartFileType;
 import com.jetbrains.lang.dart.psi.DartFile;
+import io.flutter.jxbrowser.EmbeddedJxBrowser;
+import io.flutter.jxbrowser.JxBrowserStatus;
 import io.flutter.pub.PubRoot;
 import io.flutter.pub.PubRootCache;
 import io.flutter.settings.FlutterSettings;
 import io.flutter.utils.AndroidUtils;
 import io.flutter.utils.FlutterModuleUtils;
+import io.flutter.view.EmbeddedBrowser;
+import io.flutter.view.EmbeddedJcefBrowser;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.annotations.SystemIndependent;
@@ -622,4 +626,18 @@ private static ModuleSourceOrderEntry findModuleSourceEntry(@NotNull Module modu
     }
     return null;
   }
+
+  @Nullable
+  public static EmbeddedBrowser embeddedBrowser(Project project) {
+    if (project == null || project.isDisposed()) {
+      return null;
+    }
+
+    return FlutterSettings.getInstance().isEnableJcefBrowser() ? EmbeddedJcefBrowser.getInstance(project) : EmbeddedJxBrowser.getInstance(project);
+  }
+
+  public static boolean embeddedBrowserAvailable(JxBrowserStatus status) {
+    return status.equals(JxBrowserStatus.INSTALLED) || status.equals(JxBrowserStatus.INSTALLATION_SKIPPED) && FlutterSettings.getInstance()
+      .isEnableJcefBrowser();
+  }
 }