add virtual SkTypeface::onOpenStream and override that for fontconfig

trunk/src/core/SkTypeface.cpp

Index: trunk/src/core/SkTypeface.cpp
===================================================================
--- trunk/src/core/SkTypeface.cpp	(revision 8295)
+++ trunk/src/core/SkTypeface.cpp	(working copy)
@@ -123,12 +123,12 @@
 }
 
 SkStream* SkTypeface::openStream(int* ttcIndex) const {
-    if (ttcIndex) {
-        int32_t ndx = 0;
-        (void)SkFontHost::GetFileName(fUniqueID, NULL, 0, &ndx);
-        *ttcIndex = (int)ndx;
+    int ttcIndexStorage;
+    if (NULL == ttcIndex) {
+        // So our subclasses don't need to check for null param
+        ttcIndex = &ttcIndexStorage;
     }
-    return SkFontHost::OpenStream(fUniqueID);
+    return this->onOpenStream(ttcIndex);
 }
 
 int SkTypeface::getUnitsPerEm() const {
@@ -155,6 +155,15 @@
     return upem;
 }
 
+SkStream* SkTypeface::onOpenStream(int* ttcIndex) const {
+    if (ttcIndex) {
+        int32_t ndx = 0;
+        (void)SkFontHost::GetFileName(fUniqueID, NULL, 0, &ndx);
+        *ttcIndex = (int)ndx;
+    }
+    return SkFontHost::OpenStream(fUniqueID);
+}
+
 int SkTypeface::onGetTableTags(SkFontTableTag tags[]) const { return 0; }
 size_t SkTypeface::onGetTableData(SkFontTableTag, size_t offset,
                                   size_t length, void* data) const { return 0; }