Simple fallback implementation.

chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java

Index: chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java b/chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java
index d378b5d9e34e868f9b8ab9bd59c7d364a8b6cc40..7f4fc240cf33d62afca20e062d3797004429e6cf 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java
@@ -98,13 +98,6 @@ public class DataReductionProxySettings {
     }
 
     /**
-     * Returns a configuration string for the data reduction proxy.
-     */
-    public String getDataReductionProxyAuth() {
-        return nativeGetDataReductionProxyAuth(mNativeDataReductionProxySettings);
-    }
-
-    /**
      * Sets the preference on whether to enable/disable the SPDY proxy. This will zero out the
      * data reduction statistics if this is the first time the SPDY proxy has been enabled.
      */
@@ -139,6 +132,23 @@ public class DataReductionProxySettings {
     }
 
     /**
+     * Returns true if the host and realm describe an appropriate authentication challenge

[bengr, 2013/10/22 17:49:30]

I don't know what this comment means. Please clarify. How does a host and realm
describe anything?

[marq (ping after 24h), 2013/10/22 21:18:01]

Done.

+     * for the data reduction proxy.
+     */
+    public boolean isAcceptableAuthChallenge(String host, String realm) {

[bengr, 2013/10/22 17:49:30]

What makes it an appropriate challenge? 

[marq (ping after 24h), 2013/10/22 21:18:01]

Done.

+        return nativeIsAcceptableAuthChallenge(mNativeDataReductionProxySettings, host, realm);
+    }
+
+    /**
+     * Returns a string suitable for sending back to the data reduction proxy server to act as an

[bengr, 2013/10/22 17:49:30]

Returns an authentication token for the data reduction proxy.

[marq (ping after 24h), 2013/10/22 21:18:01]

Done.

+     * authentication token. If the token cannot be generated, an empty string is returned.
+     * @return The generated token.
+     */
+    public String getTokenForAuthChallenge(String host, String realm) {
+        return nativeGetTokenForAuthChallenge(mNativeDataReductionProxySettings, host, realm);
+    }
+
+    /**
      * Retrieves the history of daily totals of bytes that would have been
      * received if no data reducing mechanism had been applied.
      * @return The history of daily totals
@@ -183,8 +193,6 @@ public class DataReductionProxySettings {
             int nativeDataReductionProxySettingsAndroid);
     private native String nativeGetDataReductionProxyOrigin(
             int nativeDataReductionProxySettingsAndroid);
-    private native String nativeGetDataReductionProxyAuth(
-            int nativeDataReductionProxySettingsAndroid);
     private native boolean nativeIsDataReductionProxyEnabled(
             int nativeDataReductionProxySettingsAndroid);
     private native boolean nativeIsDataReductionProxyManaged(
@@ -195,6 +203,10 @@ public class DataReductionProxySettings {
             int nativeDataReductionProxySettingsAndroid);
     private native ContentLengths nativeGetContentLengths(
             int nativeDataReductionProxySettingsAndroid);
+    private native boolean nativeIsAcceptableAuthChallenge(
+            int nativeDataReductionProxySettingsAndroid, String host, String realm);
+    private native String nativeGetTokenForAuthChallenge(
+            int nativeDataReductionProxySettingsAndroid, String host, String realm);
     private native long[] nativeGetDailyOriginalContentLengths(
             int nativeDataReductionProxySettingsAndroid);
     private native long[] nativeGetDailyReceivedContentLengths(