Web MIDI: move MIDI message validating logic into message_util.{cc|h}

content/browser/media/midi_host.cc

Index: content/browser/media/midi_host.cc
diff --git a/content/browser/media/midi_host.cc b/content/browser/media/midi_host.cc
index 73d131c31a655b142b217640a75f846c42adfcf4..af57a91a8e3fa0204befbd3e095530d9452015eb 100644
--- a/content/browser/media/midi_host.cc
+++ b/content/browser/media/midi_host.cc
@@ -6,7 +6,6 @@
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
-#include "base/metrics/histogram_macros.h"
 #include "base/process/process.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/bad_message.h"
@@ -15,9 +14,9 @@
 #include "content/common/media/midi_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/user_metrics.h"
+#include "media/midi/message_util.h"
 #include "media/midi/midi_manager.h"
 #include "media/midi/midi_message_queue.h"
-#include "media/midi/midi_message_util.h"
 
 namespace content {
 namespace {
@@ -32,16 +31,12 @@ const size_t kMaxInFlightBytes = 10 * 1024 * 1024;  // 10 MB.
 // how many bytes will be sent before reporting back to the renderer.
 const size_t kAcknowledgementThresholdBytes = 1024 * 1024;  // 1 MB.
 
-bool IsDataByte(uint8_t data) {
-  return (data & 0x80) == 0;
-}
-
-bool IsSystemRealTimeMessage(uint8_t data) {
-  return 0xf8 <= data && data <= 0xff;
-}
-
 }  // namespace
 
+using midi::IsDataByte;
+using midi::IsSystemRealTimeMessage;
+using midi::IsValidWebMIDIData;
+using midi::MidiPortInfo;
 using midi::kSysExByte;
 using midi::kEndOfSysExByte;
 using midi::mojom::Result;
@@ -153,14 +148,14 @@ void MidiHost::CompleteStartSession(Result result) {
   Send(new MidiMsg_SessionStarted(result));
 }
 
-void MidiHost::AddInputPort(const midi::MidiPortInfo& info) {
+void MidiHost::AddInputPort(const MidiPortInfo& info) {
   base::AutoLock auto_lock(messages_queues_lock_);
   // MidiMessageQueue is created later in ReceiveMidiData().
   received_messages_queues_.push_back(nullptr);
   Send(new MidiMsg_AddInputPort(info));
 }
 
-void MidiHost::AddOutputPort(const midi::MidiPortInfo& info) {
+void MidiHost::AddOutputPort(const MidiPortInfo& info) {
   base::AutoLock auto_lock(output_port_count_lock_);
   output_port_count_++;
   Send(new MidiMsg_AddOutputPort(info));
@@ -231,42 +226,4 @@ void MidiHost::Detach() {
   midi_manager_ = nullptr;
 }
 
-// static
-bool MidiHost::IsValidWebMIDIData(const std::vector<uint8_t>& data) {
-  bool in_sysex = false;
-  size_t sysex_start_offset = 0;
-  size_t waiting_data_length = 0;
-  for (size_t i = 0; i < data.size(); ++i) {
-    const uint8_t current = data[i];
-    if (IsSystemRealTimeMessage(current))
-      continue;  // Real time message can be placed at any point.
-    if (waiting_data_length > 0) {
-      if (!IsDataByte(current))
-        return false;  // Error: |current| should have been data byte.
-      --waiting_data_length;
-      continue;  // Found data byte as expected.
-    }
-    if (in_sysex) {
-      if (data[i] == kEndOfSysExByte) {
-        in_sysex = false;
-        UMA_HISTOGRAM_COUNTS("Media.Midi.SysExMessageSizeUpTo1MB",
-                             i - sysex_start_offset + 1);
-      } else if (!IsDataByte(current)) {
-        return false;  // Error: |current| should have been data byte.
-      }
-      continue;  // Found data byte as expected.
-    }
-    if (current == kSysExByte) {
-      in_sysex = true;
-      sysex_start_offset = i;
-      continue;  // Found SysEX
-    }
-    waiting_data_length = midi::GetMidiMessageLength(current);
-    if (waiting_data_length == 0)
-      return false;  // Error: |current| should have been a valid status byte.
-    --waiting_data_length;  // Found status byte
-  }
-  return waiting_data_length == 0 && !in_sysex;
-}
-
 }  // namespace content