Move IDB Mojo file to Blink (part 1)

Part 1 in moving the IDB Mojo file from content/common/indexed_db/
to third_party/blink/public/mojom/indexeddb/indexeddb.mojom.

This commit:
- adds the indexeddb.mojom file
- puts the new mojom in the blink mojom namespace
- updates all files that include the indexed_db.mojom.h header to
  include the new indexeddb.mojom.h as well
- moves web_idb_types.h to blink/public/common/indexeddb/

This commit converts Chromium to the following Mojom types:
- indexed_db.mojom.BlobInfo -> blink.mojom.IDBBlobInfo
- indexed_db.mojom.FileInfo -> blink.mojom.IDBFileInfo
- indexed_db.mojom.Value -> blink.mojom.IDBValue
- indexed_db.mojom.ObserverTransaction -> blink.mojom.IDBObserverTransaction
- indexed_db.mojom.OperationType -> blink.mojom.IDBOperationType
- indexed_db.mojom.CursorDirection -> blink.mojom.IDBCursorDirection
- indexed_db.mojom.DataLoss -> blink.mojom.IDBDataLoss
- indexed_db.mojom.DatalessKeyType -> blink.mojom.IDBDatalessKeyType
- indexed_db.mojom.KeyData -> blink.mojom.IDBKeyData
- indexed_db.mojom.Key -> blink.mojom.IDBKey

Bug: 717812
Change-Id: I8255e69a24c59a11fa68d173ce5bb31c2b7f51a0
Reviewed-on: https://chromium-review.googlesource.com/1173713
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Chase Phillips <cmp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583494}
97 files changed