Add an activity that allows whitelisted applications to clear all data in Chrome.

chrome/android/java_staging/AndroidManifest.xml

Index: chrome/android/java_staging/AndroidManifest.xml
diff --git a/chrome/android/java_staging/AndroidManifest.xml b/chrome/android/java_staging/AndroidManifest.xml
index 17a0d0a5f8421d57851dfe7cb738cf100e7bf888..8f7c53dcce83f1bd030aff17a5eb828e73a5d343 100644
--- a/chrome/android/java_staging/AndroidManifest.xml
+++ b/chrome/android/java_staging/AndroidManifest.xml
@@ -349,6 +349,12 @@ by a child template that "extends" this file.
             android:excludeFromRecents="true">
         </activity>
 
+        <activity android:name="org.chromium.chrome.browser.child_accounts.ResetDataActivity"

[aurimas (slooooooooow), 2015/06/09 17:45:03]

We are exporting this and we will always have to support this so we need to get
this right.

I would vote for removing the underscore from child_accounts and making it
"childaccounts"
Reasoning why:
- I could not find a single _ (underscore) in any package names in Android.
- Google style guide says not to use underscores (I know Android style guide
does not specify it, but it does not use _ either) [1]

Reasons why it is iffy:
- I know we have bad examples (like dom_distiller), but I dont think it is a
good precedent.
- It will make c++ and java directories mismatch (which we already do in several
places)

[1]
https://google-styleguide.googlecode.com/svn/trunk/javaguide.html#s5.2.1-pack...

+            android:theme="@style/Transparent"
+            android:exported="true"
+            android:excludeFromRecents="true">
+        </activity>
+
         <activity android:name="org.chromium.chrome.browser.document.CipherKeyActivity"
             android:launchMode="singleInstance"
             android:theme="@android:style/Theme.Translucent.NoTitleBar"