Make WebURLLoader capable of retaining received buffers.

content/public/child/request_peer.h

Index: content/public/child/request_peer.h
diff --git a/content/public/child/request_peer.h b/content/public/child/request_peer.h
index dfa7a7417ea3d9a6ad36c979fa3b60b1c1e305dd..17145ba0b9e1a331e068e1e5e9719155113bcd04 100644
--- a/content/public/child/request_peer.h
+++ b/content/public/child/request_peer.h
@@ -6,8 +6,10 @@
 #define CONTENT_PUBLIC_CHILD_REQUEST_PEER_H_
 
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 
 class GURL;
@@ -33,6 +35,42 @@ struct ResourceResponseInfo;
 // for more information.
 class CONTENT_EXPORT RequestPeer {
  public:
+  // This class represents data gotten from the Browser process. Each data
+  // consists of |payload|, |length| and |encoded_length|. The payload is
+  // valid only when the data instance is valid.
+  // In order to work with Chrome resource loading IPC, it is desirable to
+  // reclaim data in FIFO order in a RequestPeer in terms of performance.
+  // |payload|, |length| and |encoded_length| functions are thread-safe, but
+  // the data object itself must be destroyed on the original thread.
+  class CONTENT_EXPORT ReceivedData {
+   public:
+    virtual ~ReceivedData() {}
+    virtual const char* payload() const = 0;
+    virtual int length() const = 0;
+    // The encoded_length is the length of the encoded data transferred
+    // over the network, which could be different from data length (e.g. for
+    // gzipped content).
+    virtual int encoded_length() const = 0;
+  };
+
+  class CONTENT_EXPORT FixedReceivedData final : public ReceivedData {

[jochen (gone - plz use gerrit), 2015/06/01 13:08:28]

hum, that looks a bit odd, maybe content/public/child/fixed_received_data.h ?

[yhirano, 2015/06/02 02:08:47]

Done.

+   public:
+    FixedReceivedData(const char* data, size_t length, int encoded_length);
+    FixedReceivedData(scoped_ptr<ReceivedData> data);
+    FixedReceivedData(const std::vector<char>& data, int encoded_length);
+    ~FixedReceivedData() override;
+
+    const char* payload() const override;
+    int length() const override;
+    int encoded_length() const override;
+
+   private:
+    std::vector<char> data_;
+    int encoded_length_;
+
+    DISALLOW_COPY_AND_ASSIGN(FixedReceivedData);
+  };
+
   // Called as upload progress is made.
   // note: only for requests with upload progress enabled.
   virtual void OnUploadProgress(uint64 position, uint64 size) = 0;
@@ -59,12 +97,7 @@ class CONTENT_EXPORT RequestPeer {
 
   // Called when a chunk of response data is available. This method may
   // be called multiple times or not at all if an error occurs.
-  // The encoded_data_length is the length of the encoded data transferred
-  // over the network, which could be different from data length (e.g. for
-  // gzipped content).
-  virtual void OnReceivedData(const char* data,
-                              int data_length,
-                              int encoded_data_length) = 0;
+  virtual void OnReceivedData(scoped_ptr<ReceivedData> data) = 0;
 
   // Called when metadata generated by the renderer is retrieved from the
   // cache. This method may be called zero or one times.