Make ResourceHandler::OnWillRead able to complete asynchronously.

content/browser/loader/async_resource_handler.cc

Index: content/browser/loader/async_resource_handler.cc
diff --git a/content/browser/loader/async_resource_handler.cc b/content/browser/loader/async_resource_handler.cc
index 8168f1083a21946220a6fe746383aa9269146f91..facde3fb24f50dc9ee4cdfba78296eaa85b0dc12 100644
--- a/content/browser/loader/async_resource_handler.cc
+++ b/content/browser/loader/async_resource_handler.cc
@@ -367,21 +367,28 @@ void AsyncResourceHandler::OnWillStart(
   controller->Resume();
 }
 
-bool AsyncResourceHandler::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
-                                      int* buf_size) {
+void AsyncResourceHandler::OnWillRead(
+    scoped_refptr<net::IOBuffer>* buf,
+    int* buf_size,
+    std::unique_ptr<ResourceController> controller) {
   DCHECK(!has_controller());
 
-  // TODO(mmenke):  Should fail with ERR_INSUFFICIENT_RESOURCES here.
-  if (!CheckForSufficientResource())
-    return false;
+  if (!CheckForSufficientResource()) {
+    controller->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);

[Charlie Harrison, 2017/02/16 21:25:04]

w00t!

+    return;
+  }
 
   // Return early if InliningHelper allocates the buffer, so that we should
   // inline the data into the IPC message without allocating SharedMemory.
-  if (inlining_helper_->PrepareInlineBufferIfApplicable(buf, buf_size))
-    return true;
+  if (inlining_helper_->PrepareInlineBufferIfApplicable(buf, buf_size)) {
+    controller->Resume();
+    return;
+  }
 
-  if (!EnsureResourceBufferIsInitialized())
-    return false;
+  if (!EnsureResourceBufferIsInitialized()) {
+    controller->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);
+    return;
+  }
 
   DCHECK(buffer_->CanAllocate());
   char* memory = buffer_->Allocate(&allocation_size_);
@@ -390,7 +397,7 @@ bool AsyncResourceHandler::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
   *buf = new DependentIOBuffer(buffer_.get(), memory);
   *buf_size = allocation_size_;
 
-  return true;
+  controller->Resume();
 }
 
 void AsyncResourceHandler::OnReadCompleted(