Make Binary() construct a proper, empty instance.

Feels the most efficient way to accomplish this is to
make data() and size() return appropriate values when
impl_ isn't set.

Bug: 1026646
Change-Id: I8f9f1cb6621173ced066065f4ec6b64b5a609322
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1935430Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#718945}

third_party/blink/renderer/core/inspector/v8_inspector_string.h

@@ -113,8 +113,8 @@ class CORE_EXPORT Binary {
 
   Binary() = default;
 
-  const uint8_t* data() const { return impl_->data(); }
-  size_t size() const { return impl_->size(); }
+  const uint8_t* data() const { return impl_ ? impl_->data() : nullptr; }
+  size_t size() const { return impl_ ? impl_->size() : 0; }
 
   String toBase64() const;
   static Binary fromBase64(const String& base64, bool* success);