Add LargeIconCache and LargeIconServiceFactory for iOS.

ios/chrome/browser/favicon/large_icon_cache.mm

Index: ios/chrome/browser/favicon/large_icon_cache.mm
diff --git a/ios/chrome/browser/favicon/large_icon_cache.mm b/ios/chrome/browser/favicon/large_icon_cache.mm
new file mode 100644
index 0000000000000000000000000000000000000000..21d8743cfbe2ca1c391cf96d2142cd0c61efa681
--- /dev/null
+++ b/ios/chrome/browser/favicon/large_icon_cache.mm
@@ -0,0 +1,59 @@
+// Copyright 2015 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 "ios/chrome/browser/favicon/large_icon_cache.h"
+
+#import <Foundation/Foundation.h>
+
+#include "components/favicon_base/fallback_icon_style.h"
+#include "components/favicon_base/favicon_types.h"
+#include "url/gurl.h"
+
+namespace {
+
+const NSInteger kMaxCacheSize = 12;
+
+}  // anonymous namespace
+
+LargeIconCache::LargeIconCache(ios::ChromeBrowserState* browser_state)
+    : browser_state_(browser_state), cache_(kMaxCacheSize) {}
+
+LargeIconCache::~LargeIconCache() {}
+
+void LargeIconCache::SetCachedResult(
+    GURL url,
+    const favicon_base::LargeIconResult& result) {
+  favicon_base::LargeIconResult* cache_value;

[sdefresne, 2015/10/29 16:45:25]

scoped_ptr<favicon_base::LargeIconResult> cache_value;

[justincohen, 2015/10/29 20:32:17]

Removed completely

+  if (result.bitmap.is_valid()) {
+    cache_value = new favicon_base::LargeIconResult(result.bitmap);
+  } else {
+    scoped_ptr<favicon_base::FallbackIconStyle> fallback_icon_style;
+    fallback_icon_style.reset(new favicon_base::FallbackIconStyle);
+    fallback_icon_style->background_color =
+        result.fallback_icon_style->background_color;
+    fallback_icon_style->text_color = result.fallback_icon_style->text_color;
+    cache_value =
+        new favicon_base::LargeIconResult(fallback_icon_style.release());
+  }
+
+  CacheEntry* entry = new CacheEntry;
+  entry->result.reset(cache_value);
+  cache_.Put(url, entry);
+}
+
+scoped_ptr<favicon_base::LargeIconResult> LargeIconCache::GetCachedResult(
+    GURL url) {
+  base::OwningMRUCache<GURL, CacheEntry*>::iterator iter = cache_.Get(url);
+  if (iter != cache_.end()) {
+    return iter->second->result.Pass();

[sdefresne, 2015/10/29 16:45:25]

You're sinking the reference here (since result is a scoped_ptr<>), so I think
you should do the following:

if (iter != cache_.end()) {
  scoped_ptr<favicon_base::LargeIconResult> result(
      iter->second->result.Pass());
  cache_.Erase(iter);
  return result;
}

[justincohen, 2015/10/29 20:32:17]

Changed to not Pass what we hold on to.

+  }
+
+  // Otherwise, return an empty cache value.
+  scoped_ptr<favicon_base::LargeIconResult> cache_value;
+  return cache_value.Pass();

[sdefresne, 2015/10/29 16:45:25]

return scoped_ptr<favicon_base::LargeIconResult>();

[justincohen, 2015/10/29 20:32:17]

Done.

+}
+
+LargeIconCache::CacheEntry::CacheEntry() {}
+
+LargeIconCache::CacheEntry::~CacheEntry() {}