[blimp] Change to use SHA-256 instead of SHA-1 for unique ids

blimp/common/blob_cache/in_memory_blob_cache.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "blimp/common/blob_cache/in_memory_blob_cache.h"
 
 #include "base/logging.h"
-#include "base/sha1.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
 
 namespace blimp {
 
 InMemoryBlobCache::InMemoryBlobCache() {}
 
 InMemoryBlobCache::~InMemoryBlobCache() {}
 
 void InMemoryBlobCache::Put(const BlobId& id, BlobDataPtr data) {
   if (Contains(id)) {
     // In cases where the engine has miscalculated what is already available
@@ skipping 11 matching lines @@
 
 BlobDataPtr InMemoryBlobCache::Get(const BlobId& id) const {
   if (!Contains(id)) {
     return nullptr;
   }
 
   return cache_.find(id)->second;
 }
 
 }  // namespace blimp