pdfviewer: track what objects have been used during rendering. It will be the base of reporting unused objects to warn about ineficiencies in pdf generations, tests, and what features are not implemented fully.

Review URL: https://codereview.chromium.org/23601017

git-svn-id: http://skia.googlecode.com/svn/trunk@11100 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/PdfViewer/pdfparser/native/SkPdfNativeObject.cpp b/experimental/PdfViewer/pdfparser/native/SkPdfNativeObject.cpp
index 5a1a6ca..9411368 100644
--- a/experimental/PdfViewer/pdfparser/native/SkPdfNativeObject.cpp
+++ b/experimental/PdfViewer/pdfparser/native/SkPdfNativeObject.cpp
@@ -66,6 +66,8 @@
 }
 
 bool SkPdfNativeObject::filterStream() {
+    SkPdfMarkObjectUsed();
+
     if (!hasStream()) {
         return false;
     }
@@ -100,6 +102,10 @@
 }
 
 void SkPdfNativeObject::releaseData() {
+    // TODO(edisonn): report here unused objects
+
+    SkPdfMarkObjectUnused();
+
     if (fData) {
         switch (fDataType) {
             case kFont_Data: