[net/] default member initializers manual fix

This CL is created manually by checking the files which match the
regular expressions "^ +:? +[a-z][A-Za-z_]+\([A-Za-z_:]+\)(,$| \{)",
"^ +[a-z][A-Za-z_]+\(base::[A-Za-z_]+\(\d+\)\)".

This CL fixes default member initializers for raw_ptr<> and some enum
types. And also removes unnecessary null initialization of unique_ptr<>
and scoped_refptr<>.

This should cause no functional changes.

Bug: 1334056
Change-Id: Ia434e79be1f8c9a6d4b01a1a215f7ff7e13302ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3695879
Reviewed-by: Kenichi Ishibashi <[email protected]>
Commit-Queue: Tsuyoshi Horo <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1012413}
diff --git a/net/base/io_buffer.cc b/net/base/io_buffer.cc
index 78d4cf4..26e0e02 100644
--- a/net/base/io_buffer.cc
+++ b/net/base/io_buffer.cc
@@ -68,12 +68,12 @@
 }
 
 DrainableIOBuffer::DrainableIOBuffer(scoped_refptr<IOBuffer> base, int size)
-    : IOBuffer(base->data()), base_(std::move(base)), size_(size), used_(0) {
+    : IOBuffer(base->data()), base_(std::move(base)), size_(size) {
   AssertValidBufferSize(size);
 }
 
 DrainableIOBuffer::DrainableIOBuffer(scoped_refptr<IOBuffer> base, size_t size)
-    : IOBuffer(base->data()), base_(std::move(base)), size_(size), used_(0) {
+    : IOBuffer(base->data()), base_(std::move(base)), size_(size) {
   AssertValidBufferSize(size);
 }