I am writing an application for a client that will have several devices that are open to customers to look at and play with. They want to be able to clear the browser history on
I tried to close the browser via the ActivityManager and it works fine. I tested this on an HTC 2.2 and it works perfect.
Maybe you should also try this:
am.killBackgroundProcesses("com.google.android.browser");
in case the browser on your phone is not at com.android.browser
or even try to finish the activity: com.android.browser.BrowserActivity
Hope this helps!