Run the later parts of startup as UI thread tasks

content/public/android/java/src/org/chromium/content/browser/AndroidBrowserProcess.java

Index: content/public/android/java/src/org/chromium/content/browser/AndroidBrowserProcess.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/AndroidBrowserProcess.java b/content/public/android/java/src/org/chromium/content/browser/AndroidBrowserProcess.java
index bf046f9751525369b574e7c7195b943c0ef551f4..9c8d47ce83055161e288474dfe7dc7e0390180b8 100644
--- a/content/public/android/java/src/org/chromium/content/browser/AndroidBrowserProcess.java
+++ b/content/public/android/java/src/org/chromium/content/browser/AndroidBrowserProcess.java
@@ -45,10 +45,13 @@ public class AndroidBrowserProcess {
      * MAX_RENDERERS_SINGLE_PROCESS requests single-process mode where the renderer will run in the
      * application process in a separate thread. The maximum number of allowed renderers is capped
      * by MAX_RENDERERS_LIMIT.
-     *
+     * @param mustBeImmediate true if initialization must be completed without creating additional
+     * UI tasks
+     * @param observer startup observer provides callback when startup complete
      * @return Whether the process actually needed to be initialized (false if already running).
      */
-     public static boolean init(Context context, int maxRendererProcesses)
+     public static boolean init(Context context, int maxRendererProcesses, boolean mustBeImmediate,
+             StartupObserver observer)
              throws ProcessInitException {
         assert maxRendererProcesses >= 0;
         assert maxRendererProcesses <= MAX_RENDERERS_LIMIT;
@@ -75,11 +78,27 @@ public class AndroidBrowserProcess {
         nativeSetCommandLineFlags(maxRendererProcesses,
                 nativeIsPluginEnabled() ? getPlugins(context) : null);
         ContentMain.initApplicationContext(appContext);
-        int result = ContentMain.start();
+
+        if(observer == null) {
+            // Create a default observer that does nothing
+            observer = new StartupObserver();
+        }
+
+        int result = ContentMain.start(mustBeImmediate, observer);
         if (result > 0) throw new ProcessInitException(result);
         return true;
     }
 
+    /*
+     * Old version of init, kept short term to simplify change to new version
+     * TODO (aberent) : remove this once callers updated.
+     */
+    @Deprecated
+    public static boolean init(Context context, int maxRendererProcesses)
+             throws ProcessInitException {
+        return init(context, maxRendererProcesses, true, null);
+    }
+
     /**
      * Initialization needed for tests. Mainly used by content browsertests.
      */