Roll Chrome into Mojo.

net/http/partial_data.cc

Index: net/http/partial_data.cc
diff --git a/net/http/partial_data.cc b/net/http/partial_data.cc
index 247d76b5e935a5da6eea91ee2062f99d6bf52029..f0615d5ac335b4d42bdbdc8a188d417a07e6733a 100644
--- a/net/http/partial_data.cc
+++ b/net/http/partial_data.cc
@@ -103,7 +103,12 @@ void PartialData::Core::OnIOComplete(int result) {
 // -----------------------------------------------------------------------------
 
 PartialData::PartialData()
-    : range_present_(false),
+    : current_range_start_(0),
+      current_range_end_(0),
+      cached_start_(0),
+      resource_size_(0),
+      cached_min_len_(0),
+      range_present_(false),
       final_range_(false),
       sparse_entry_(true),
       truncated_(false),
@@ -130,7 +135,6 @@ bool PartialData::Init(const HttpRequestHeaders& headers) {
   if (!byte_range_.IsValid())
     return false;
 
-  resource_size_ = 0;
   current_range_start_ = byte_range_.first_byte_position();
 
   DVLOG(1) << "Range start: " << current_range_start_ << " end: " <<
@@ -222,19 +226,20 @@ void PartialData::PrepareCacheValidation(disk_cache::Entry* entry,
   if (current_range_start_ == cached_start_) {
     // The data lives in the cache.
     range_present_ = true;
+    current_range_end_ = cached_start_ + cached_min_len_ - 1;
     if (len == cached_min_len_)
       final_range_ = true;
     headers->SetHeader(
         HttpRequestHeaders::kRange,
-        net::HttpByteRange::Bounded(
-            current_range_start_,
-            cached_start_ + cached_min_len_ - 1).GetHeaderValue());
+        HttpByteRange::Bounded(current_range_start_, current_range_end_)
+            .GetHeaderValue());
   } else {
     // This range is not in the cache.
+    current_range_end_ = cached_start_ - 1;
     headers->SetHeader(
         HttpRequestHeaders::kRange,
-        net::HttpByteRange::Bounded(
-            current_range_start_, cached_start_ - 1).GetHeaderValue());
+        HttpByteRange::Bounded(current_range_start_, current_range_end_)
+            .GetHeaderValue());
   }
 }
 
@@ -286,6 +291,9 @@ bool PartialData::UpdateFromStoredHeaders(const HttpResponseHeaders* headers,
     return true;
   }
 
+  if (!headers->HasStrongValidators())
+    return false;
+
   int64 length_value = headers->GetContentLength();
   if (length_value <= 0)
     return false;  // We must have stored the resource length.
@@ -371,7 +379,21 @@ bool PartialData::ResponseHeadersOK(const HttpResponseHeaders* headers) {
   if (start != current_range_start_)
     return false;
 
-  if (byte_range_.IsValid() && end > byte_range_.last_byte_position())
+  if (!current_range_end_) {
+    // There is nothing in the cache.
+    DCHECK(byte_range_.HasLastBytePosition());
+    current_range_end_ = byte_range_.last_byte_position();
+    if (current_range_end_ >= resource_size_) {
+      // We didn't know the real file size, and the server is saying that the
+      // requested range goes beyond the size. Fix it.
+      current_range_end_ = end;
+      byte_range_.set_last_byte_position(end);
+    }
+  }
+
+  // If we received a range, but it's not exactly the range we asked for, avoid
+  // trouble and signal an error.
+  if (end != current_range_end_)
     return false;
 
   return true;