Revert of Implement lossy pref behavior for JsonPrefStore.

base/prefs/json_pref_store.cc

Index: base/prefs/json_pref_store.cc
diff --git a/base/prefs/json_pref_store.cc b/base/prefs/json_pref_store.cc
index 40e3052836588dff6b22089ddb278be7f64d89af..8ce59745536d02fe4af6279a3d85312966a34937 100644
--- a/base/prefs/json_pref_store.cc
+++ b/base/prefs/json_pref_store.cc
@@ -158,7 +158,6 @@
       pref_filter_(pref_filter.Pass()),
       initialized_(false),
       filtering_in_progress_(false),
-      pending_lossy_write_(false),
       read_error_(PREF_READ_ERROR_NONE),
       write_count_histogram_(writer_.commit_interval(), path_) {
   DCHECK(!path_.empty());
@@ -253,7 +252,8 @@
   prefs_->Get(key, &old_value);
   if (!old_value || !value->Equals(old_value)) {
     prefs_->Set(key, new_value.release());
-    ScheduleWrite(flags);
+    if (!read_only_)
+      writer_.ScheduleWrite(this);
   }
 }
 
@@ -268,7 +268,8 @@
   DCHECK(CalledOnValidThread());
 
   prefs_->RemovePath(key, NULL);
-  ScheduleWrite(flags);
+  if (!read_only_)
+    writer_.ScheduleWrite(this);
 }
 
 bool JsonPrefStore::ReadOnly() const {
@@ -308,11 +309,6 @@
 void JsonPrefStore::CommitPendingWrite() {
   DCHECK(CalledOnValidThread());
 
-  // Schedule a write for any lossy writes that are outstanding to ensure that
-  // they get flushed when this function is called.
-  if (pending_lossy_write_)
-    writer_.ScheduleWrite(this);
-
   if (writer_.HasPendingWrite() && !read_only_)
     writer_.DoScheduledWrite();
 }
@@ -325,7 +321,8 @@
 
   FOR_EACH_OBSERVER(PrefStore::Observer, observers_, OnPrefValueChanged(key));
 
-  ScheduleWrite(flags);
+  if (!read_only_)
+    writer_.ScheduleWrite(this);
 }
 
 void JsonPrefStore::RegisterOnNextSuccessfulWriteCallback(
@@ -404,8 +401,6 @@
 bool JsonPrefStore::SerializeData(std::string* output) {
   DCHECK(CalledOnValidThread());
 
-  pending_lossy_write_ = false;
-
   write_count_histogram_.RecordWriteOccured();
 
   if (pref_filter_)
@@ -437,8 +432,8 @@
 
   initialized_ = true;
 
-  if (schedule_write)
-    ScheduleWrite(DEFAULT_PREF_WRITE_FLAGS);
+  if (schedule_write && !read_only_)
+    writer_.ScheduleWrite(this);
 
   if (error_delegate_ && read_error_ != PREF_READ_ERROR_NONE)
     error_delegate_->OnError(read_error_);
@@ -448,16 +443,6 @@
                     OnInitializationCompleted(true));
 
   return;
-}
-
-void JsonPrefStore::ScheduleWrite(uint32 flags) {
-  if (read_only_)
-    return;
-
-  if (flags & LOSSY_PREF_WRITE_FLAG)
-    pending_lossy_write_ = true;
-  else
-    writer_.ScheduleWrite(this);
 }
 
 // NOTE: This value should NOT be changed without renaming the histogram