Cache backend for devices with flash storage

net/disk_cache/flash/segment.cc

Index: net/disk_cache/flash/segment.cc
diff --git a/net/disk_cache/flash/segment.cc b/net/disk_cache/flash/segment.cc
index a63a5a39985d077b7eca9393321204e57eddfa0f..b00b38a5209c64fac7fdca02727170d41ccbe0c8 100644
--- a/net/disk_cache/flash/segment.cc
+++ b/net/disk_cache/flash/segment.cc
@@ -18,17 +18,19 @@ Segment::Segment(int32 index, bool read_only, Storage* storage)
       write_offset_(offset_) {
   DCHECK(storage);
   DCHECK(storage->size() % kFlashSegmentSize == 0);
-  DCHECK(offset_ >= 0 && offset_ + kFlashSegmentSize <= storage->size());
 }
 
 Segment::~Segment() {
-  DCHECK(read_only_);
+  DCHECK(!init_ || read_only_);
 }
 
 bool Segment::Init() {
   if (init_)
     return false;
 
+  if (offset_ < 0 || offset_ + kFlashSegmentSize > storage_->size())
+    return false;
+
   if (!read_only_) {
     init_ = true;
     return true;
@@ -82,6 +84,7 @@ bool Segment::Close() {
   DCHECK(header_offsets_.size() <= kFlashMaxEntryCount);
 
   int32 summary[kFlashMaxEntryCount + 1];
+  memset(summary, 0, kFlashSummarySize);
   summary[0] = header_offsets_.size();
   std::copy(header_offsets_.begin(), header_offsets_.end(), summary + 1);
   if (!storage_->Write(summary, kFlashSummarySize, summary_offset_))