[DevTools] Rename Binary::createFromBase64 -> fromBase64.

This will be more consistent with other creation methods,
as discovered in
https://chromium-review.googlesource.com/c/chromium/src/+/1281166/4/headless/lib/browser/protocol/protocol_string.h

Sorry about the Churn. And it turns out I was wrong I'll have to
send one more PR for two other renames. Sorry!

Bug: chromium:891377
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I10ed870bcf065c1913971ec8c194fa1c8149a2b4
Reviewed-on: https://chromium-review.googlesource.com/c/1284789Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56708}

src/inspector/string-util.h

@@ -70,7 +70,7 @@ class Binary {
   const uint8_t* data() const { UNIMPLEMENTED(); }
   size_t size() const { UNIMPLEMENTED(); }
   String toBase64() const { UNIMPLEMENTED(); }
-  static Binary createFromBase64(const String& base64, bool* success) {
+  static Binary fromBase64(const String& base64, bool* success) {
     UNIMPLEMENTED();
   }
 };