Issue with hot reloading while debugging

## Steps to Reproduce

1) Run app in debug mode
2) Attempt to hot reload (Seems to happen more when paused on a breakpoint, but in general happens when you have a debugger attached)
3) Notice it never reloads

## Version info

```
[√] Flutter (Channel beta, v0.3.1, on Microsoft Windows [Version 10.0.16299.125], locale en-US)
• Flutter version 0.3.1 at C:\Users\pobor\Documents\flutter
• Framework revision 12bbaba9ae (3 weeks ago), 2018-04-19 23:36:15 -0700
• Engine revision 09d05a3891
• Dart version 2.0.0-dev.48.0.flutter-fe606f890b

[√] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at C:\Users\pobor\AppData\Local\Android\sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-27, build-tools 27.0.3
• Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
• All Android licenses accepted.

[√] Android Studio (version 3.1)
• Android Studio at C:\Program Files\Android\Android Studio
• Flutter plugin version 24.2.1
• Dart plugin version 173.4700
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] IntelliJ IDEA Ultimate Edition (version 2018.1)
• IntelliJ at C:\Users\pobor\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\181.4668.68
• Flutter plugin version 24.0.2
• Dart plugin version 181.4668.60

[√] Connected devices (1 available)
• Android SDK built for x86 • emulator-5554 • android-x86 • Android 8.1.0 (API 27) (emulator)

• No issues found!
```

Start by reproducing the failure in Flutter debug mode on the reported Windows and Android emulator setup, especially while paused at a breakpoint or with a debugger attached. Trace the hot-reload request through the IntelliJ Flutter plugin; done means hot reload completes reliably in those debugging states.

Written by the indexing model from the issue text.