When sending resources across the IPC barrier, use increasing sized buffers.

chrome/browser/renderer_host/async_resource_handler.h

Index: chrome/browser/renderer_host/async_resource_handler.h
diff --git a/chrome/browser/renderer_host/async_resource_handler.h b/chrome/browser/renderer_host/async_resource_handler.h
index 17e9260ff5f8512c5da3a7dc6cc2522132ed4806..b946d4d70a8b7dc5979961d6e1dc823fd7427d8b 100644
--- a/chrome/browser/renderer_host/async_resource_handler.h
+++ b/chrome/browser/renderer_host/async_resource_handler.h
@@ -46,6 +46,12 @@ class AsyncResourceHandler : public ResourceHandler {
   base::ProcessHandle process_handle_;
   ResourceDispatcherHost* rdh_;
 
+  // We exponentially grow the size of the buffer allocated. On the first
+  // OnWillRead() call, we allocate a buffer of 32k and double it on each
+  // subsequent call, up to a maximum size of 512k. |next_buffer_size_| is the
+  // size of the buffer to be allocated on the next OnWillRead() call.
+  int next_buffer_size_;
+
   DISALLOW_COPY_AND_ASSIGN(AsyncResourceHandler);
 };