I was using the following code on my application to set my home icon to a specific drawable:
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setIcon(R.drawable.ic_menu);
getSupportActionBar().setDisplayShowTitleEnabled(false);
But I was having problems with the "lag" between "creating the decor view and my onCreate executing" as explained here by Jake Wharton: ActionBar Lag in hiding title
On the link above the solution was to create a new style, and declare it in the Manifest, and so I did:
<resources>
<style name="AppTheme" parent="android:Theme.Light" />
<style name="WATheme" parent="Theme.Sherlock.Light">
    <item name="android:actionBarStyle">@style/WATheme.ActionBar</item>
    <item name="actionBarStyle">@style/WATheme.ActionBar</item>
</style>
<style name="WATheme.ActionBar" parent="Widget.Sherlock.Light.ActionBar.Solid">
    <item name="android:displayOptions">homeAsUp|showHome</item>
    <item name="displayOptions">homeAsUp|showHome</item>
</style>
</resources>
Manifest:
<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:theme="@style/WATheme"
        android:label="@string/title_activity_main" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>
It is now working fine, I have my home button with up configuration, but I still want to change the icon to another specific drawable, only in this activity, without having to change any android:icon in the Manifest. How can I achieve that?
Hope it was clear enough. Thank you.