Implement AAPT Bundle format

AAPT will scan XML files looking for the <aapt:attr> XML tag.

<!-- @layout/bundle.xml -->
<ImageView xmlns:aapt="http://schemas.android.com/aapt">
  <aapt:attr name="android:src">
    <vector android:pathData="..." ...>
    </vector>
  </aapt:attr>
</ImageView>

The SINGLE child element of the <aapt:attr> tag is extracted into its own top
level resource. It is given a generated name.

The parent element of <aapt:attr> is then given the resource attribute that was assigned
to the `name' attribute. The value is set to a reference to the generated resource.

<!-- @layout/bundle.xml -->
<ImageView android:src="@drawable/bundle_1.xml">
</ImageView>

<!-- @layout/bundle_1.xml -->
<vector android:pathData="..." ...>
</vector>

Bug:22627686
Change-Id: I8575fc4f739011402662fbf6b3db96df0012f598

tools/aapt/XMLNode.cpp

@@ -693,6 +693,12 @@ const Vector<sp<XMLNode> >& XMLNode::getChildren() const
     return mChildren;
 }
 
+
+Vector<sp<XMLNode> >& XMLNode::getChildren()
+{
+    return mChildren;
+}
+
 const String8& XMLNode::getFilename() const
 {
     return mFilename;
@@ -717,6 +723,18 @@ const XMLNode::attribute_entry* XMLNode::getAttribute(const String16& ns,
     return NULL;
 }
 
+bool XMLNode::removeAttribute(const String16& ns, const String16& name)
+{
+    for (size_t i = 0; i < mAttributes.size(); i++) {
+        const attribute_entry& ae(mAttributes.itemAt(i));
+        if (ae.ns == ns && ae.name == name) {
+            removeAttribute(i);
+            return true;
+        }
+    }
+    return false;
+}
+
 XMLNode::attribute_entry* XMLNode::editAttribute(const String16& ns,
         const String16& name)
 {