Fix proguard logic, set proguard config only when proguard is enabled.

build/android/ant/chromium-apk.xml

Index: build/android/ant/chromium-apk.xml
diff --git a/build/android/ant/chromium-apk.xml b/build/android/ant/chromium-apk.xml
index d295dc94840abf26e4ba9a623543e2fce649f17c..daae5ab23db968a2038e1844ca7b3d7f98b4c37f 100644
--- a/build/android/ant/chromium-apk.xml
+++ b/build/android/ant/chromium-apk.xml
@@ -40,8 +40,17 @@
   <property-value name="version.code" value="${APP_MANIFEST_VERSION_CODE}"/>
   <property-value name="version.name" value="${APP_MANIFEST_VERSION_NAME}"/>
 
-  <property name="proguard.config" value="${PROGUARD_FLAGS}"/>
-  <property name="proguard.enabled" value="${PROGUARD_ENABLED}"/>
+  <!--
+    We use the PROGUARD_ENABLED flag for enabling proguard. By default proguard is enabled for
+    Release builds if proguard.config is set. Setting proguard.config even to an empty string will
+    enable proguard. Set this property only when we have explicitly enabled proguard.
+  -->
+  <condition property="proguard.config"
+      value="${PROGUARD_FLAGS}">
+    <and>

[cjhopman, 2012/10/12 00:39:56]

I don't think the <and> block is needed.

[shashi, 2012/10/12 00:48:43]

Nice catch, thanks. I had one more condition here, which was redundant, I
removed it but left this here.
On 2012/10/12 00:39:56, cjhopman wrote:

+      <istrue value="${PROGUARD_ENABLED}"/>
+    </and>
+  </condition>
   <!-- TODO(shashishekhar): Enable emma and code-coverage filters. -->
 
   <condition property="asset.absolute.dir"