Address comments left on r581994

Somehow these changes didn't make into the last patchset uploaded for
r581994 and so I have recreated them here.

Change-Id: I54cf951d46ad12c23433996dee790ce25047c8a5
Reviewed-on: https://chromium-review.googlesource.com/1187020Reviewed-by: Matt Reynolds <mattreynolds@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585614}

services/device/hid/hid_connection.cc

@@ -63,23 +63,6 @@ bool HasProtectedCollection(
 
 }  // namespace
 
-struct HidConnection::PendingHidReport {
-  PendingHidReport() = default;
-  PendingHidReport(const PendingHidReport& other) = default;
-  ~PendingHidReport() = default;
-
-  scoped_refptr<base::RefCountedBytes> buffer;
-  size_t size;
-};
-
-struct HidConnection::PendingHidRead {
-  PendingHidRead() = default;
-  PendingHidRead(PendingHidRead&& other) = default;
-  ~PendingHidRead() = default;
-
-  HidConnection::ReadCallback callback;
-};
-
 HidConnection::HidConnection(scoped_refptr<HidDeviceInfo> device_info)
     : device_info_(device_info), closed_(false) {
   has_protected_collection_ =
@@ -107,9 +90,7 @@ void HidConnection::Read(ReadCallback callback) {
     return;
   }
 
-  PendingHidRead pending_read;
-  pending_read.callback = std::move(callback);
-  pending_reads_.push(std::move(pending_read));
+  pending_reads_.emplace(std::move(callback));
   ProcessReadQueue();
 }
 
@@ -210,10 +191,7 @@ void HidConnection::ProcessInputReport(
   if (IsReportIdProtected(report_id))
     return;
 
-  PendingHidReport report;
-  report.buffer = buffer;
-  report.size = size;
-  pending_reports_.push(report);
+  pending_reports_.emplace(buffer, size);
   ProcessReadQueue();
 }
 
@@ -224,12 +202,15 @@ void HidConnection::ProcessReadQueue() {
   // during the loop.
   scoped_refptr<HidConnection> self(this);
   while (pending_reads_.size() && pending_reports_.size()) {
-    PendingHidRead read = std::move(pending_reads_.front());
-    PendingHidReport report = std::move(pending_reports_.front());
+    ReadCallback callback = std::move(pending_reads_.front());
+
+    scoped_refptr<base::RefCountedBytes> buffer;
+    size_t size;
+    std::tie(buffer, size) = std::move(pending_reports_.front());
 
     pending_reads_.pop();
     pending_reports_.pop();
-    std::move(read.callback).Run(true, std::move(report.buffer), report.size);
+    std::move(callback).Run(true, std::move(buffer), size);
   }
 }
 

services/device/hid/hid_connection.h

@@ -7,6 +7,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <tuple>
 
 #include "base/callback_forward.h"
 #include "base/containers/queue.h"
@@ -83,16 +84,14 @@ class HidConnection : public base::RefCountedThreadSafe<HidConnection> {
   void ProcessReadQueue();
 
  private:
-  struct PendingHidReport;
-  struct PendingHidRead;
-
   scoped_refptr<HidDeviceInfo> device_info_;
   bool has_protected_collection_;
   base::ThreadChecker thread_checker_;
   bool closed_;
 
-  base::queue<PendingHidReport> pending_reports_;
-  base::queue<PendingHidRead> pending_reads_;
+  base::queue<std::tuple<scoped_refptr<base::RefCountedBytes>, size_t>>
+      pending_reports_;
+  base::queue<ReadCallback> pending_reads_;
 
   DISALLOW_COPY_AND_ASSIGN(HidConnection);
 };

services/device/hid/hid_connection_win.cc

@@ -44,6 +44,7 @@ class PendingHidTransfer : public base::win::ObjectWatcher::Delegate {
   // Implements base::win::ObjectWatcher::Delegate.
   void OnObjectSignaled(HANDLE object) override;
 
+ private:
   // The buffer isn't used by this object but it's important that a reference
   // to it is held until the transfer completes.
   scoped_refptr<base::RefCountedBytes> buffer_;
@@ -52,7 +53,6 @@ class PendingHidTransfer : public base::win::ObjectWatcher::Delegate {
   base::win::ScopedHandle event_;
   base::win::ObjectWatcher watcher_;
 
- private:
   DISALLOW_COPY_AND_ASSIGN(PendingHidTransfer);
 };
 
@@ -241,7 +241,6 @@ void HidConnectionWin::OnWriteComplete(WriteCallback callback,
   DWORD bytes_transferred;
   if (signaled && GetOverlappedResult(file_.Get(), transfer->GetOverlapped(),
                                       &bytes_transferred, FALSE)) {
-    DCHECK_LE(bytes_transferred, transfer->buffer_->size());
     std::move(callback).Run(true);
   } else {
     HID_PLOG(EVENT) << "HID write failed";