Reduce the memory usage of bookmarks storage

components/bookmarks/browser/bookmark_codec.cc

Index: components/bookmarks/browser/bookmark_codec.cc
diff --git a/components/bookmarks/browser/bookmark_codec.cc b/components/bookmarks/browser/bookmark_codec.cc
index abbb1cd7b64289eceba9eff25a87872d786d9304..0a2d744c32f9d9eb3e096ac41f57b696859b087b 100644
--- a/components/bookmarks/browser/bookmark_codec.cc
+++ b/components/bookmarks/browser/bookmark_codec.cc
@@ -13,6 +13,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
+#include "base/sys_info.h"
 #include "base/values.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/strings/grit/components_strings.h"
@@ -433,6 +434,13 @@ void BookmarkCodec::DecodeMetaInfoHelper(
     const std::string& prefix,
     BookmarkNode::MetaInfoMap* meta_info_map) {
   for (base::DictionaryValue::Iterator it(dict); !it.IsAtEnd(); it.Advance()) {
+    // Do not load the image and page data into memory for low-end devices.
+    if (base::SysInfo::IsLowEndDevice() &&

[sky, 2017/05/12 20:00:13]

If we're going to support disabling this feature I would rather the disabling is
explicit rather than keying off IsLowEndDevice. Similarly, the set of keys that
are not needed should be passed in, not hard coded here.

[ssid, 2017/05/25 00:27:27]

So, I moved the strings to storage.cc and passed it as argument to this class
when needed. Do you mean I should disable these meta info for all platforms and
all types of devices instead of just low-end devices?
Sorry I did not fully understand your comment.

+        (it.key().find("imageData") != std::string::npos ||
+         it.key().find("pageData") != std::string::npos)) {
+      continue;
+    }
+
     if (it.value().IsType(base::Value::Type::DICTIONARY)) {
       const base::DictionaryValue* subdict;
       it.value().GetAsDictionary(&subdict);