Add chunked uploads support to SPDY

net/base/upload_data_stream.cc

Index: net/base/upload_data_stream.cc
diff --git a/net/base/upload_data_stream.cc b/net/base/upload_data_stream.cc
index 9f7bdbb419a28d63610b9235c0d5fcd9a6b5952e..81e23c58cc4af662e587e55eaa563110d5e5b1a6 100644
--- a/net/base/upload_data_stream.cc
+++ b/net/base/upload_data_stream.cc
@@ -69,8 +69,13 @@ int UploadDataStream::FillBuf() {
 
       size_t bytes_copied = std::min(count, size_remaining);
 
-      memcpy(buf_->data() + buf_len_, &d[next_element_offset_], bytes_copied);
-      buf_len_ += bytes_copied;
+      // Check if we have anything to copy first, because we are getting the
+      // address of an element in |d| and that will throw an exception if |d|
+      // is an empty vector.
+      if (bytes_copied) {
+        memcpy(buf_->data() + buf_len_, &d[next_element_offset_], bytes_copied);
+        buf_len_ += bytes_copied;
+      }
 
       if (bytes_copied == count) {
         advance_to_next_element = true;