Limit the total memory usage for Stream instances

content/browser/streams/stream.h

Index: content/browser/streams/stream.h
diff --git a/content/browser/streams/stream.h b/content/browser/streams/stream.h
index 85edc8840817c3a7d8fde67a1ed0a36eb9caa587..d4b800e8ae818ac57681d9c46aa76e35161fa4fa 100644
--- a/content/browser/streams/stream.h
+++ b/content/browser/streams/stream.h
@@ -81,6 +81,11 @@ class CONTENT_EXPORT Stream : public base::RefCountedThreadSafe<Stream> {
 
   const GURL& url() const { return url_; }
 
+  // For StreamRegistry to remember the last memory usage reported to it.
+  size_t last_total_buffered_bytes() const {
+    return last_total_buffered_bytes_;
+  }
+
  private:
   friend class base::RefCountedThreadSafe<Stream>;
 
@@ -97,6 +102,10 @@ class CONTENT_EXPORT Stream : public base::RefCountedThreadSafe<Stream> {
   scoped_refptr<net::IOBuffer> data_;
   size_t data_length_;
 
+  // Last value returned by writer_->TotalBufferedBytes() in AddData(). Stored
+  // in order to check memory usage.
+  size_t last_total_buffered_bytes_;
+
   scoped_ptr<ByteStreamWriter> writer_;
   scoped_ptr<ByteStreamReader> reader_;