Sparse IO: Allow failover to network in debug builds

net/http/http_cache_transaction.cc

 // Copyright (c) 2012 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 "net/http/http_cache_transaction.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 1512 matching lines @@
 
 int HttpCache::Transaction::DoCacheQueryData() {
   next_state_ = STATE_CACHE_QUERY_DATA_COMPLETE;
 
   // Balanced in DoCacheQueryDataComplete.
   return ResetCacheIOStart(
       entry_->disk_entry->ReadyForSparseIO(io_callback_));
 }
 
 int HttpCache::Transaction::DoCacheQueryDataComplete(int result) {
+#if defined(OS_ANDROID)
+  if (result == ERR_NOT_IMPLEMENTED) {
+    // Restart the request overwriting the cache entry.
+    //
+    // Note: this would have fixed range requests for debug builds on all OSes,
+    // not just Android, but karen@ prefers to limit the effect based on OS for
+    // cherry-picked fixes.
+    // TODO(pasko): remove the OS_ANDROID limitation as soon as the fix proves
+    // useful after the cherry-pick.
+    // TODO(pasko): remove this workaround as soon as the SimpleBackendImpl
+    // supports Sparse IO.
+    return DoRestartPartialRequest();
+  }
+#endif
   DCHECK_EQ(OK, result);
   if (!cache_.get())
     return ERR_UNEXPECTED;
 
   return ValidateEntryHeadersAndContinue();
 }
 
 int HttpCache::Transaction::DoCacheReadData() {
   DCHECK(entry_);
   next_state_ = STATE_CACHE_READ_DATA_COMPLETE;
@@ skipping 1052 matching lines @@
 void HttpCache::Transaction::ResetNetworkTransaction() {
   DCHECK(!old_network_trans_load_timing_);
   DCHECK(network_trans_);
   LoadTimingInfo load_timing;
   if (network_trans_->GetLoadTimingInfo(&load_timing))
     old_network_trans_load_timing_.reset(new LoadTimingInfo(load_timing));
   network_trans_.reset();
 }
 
 }  // namespace net