Simplify apps by moving some commonly used types into Microsoft.AspNetCore.Blazor namespace

samples/StandaloneApp/App.cshtml

@@ -1,5 +1,4 @@
-@using Microsoft.AspNetCore.Blazor.Routing
-<!--
+<!--
     Configuring this stuff here is temporary. Later we'll move the app config
     into Program.cs, and it won't be necessary to specify AppAssembly.
 -->

samples/StandaloneApp/Pages/FetchData.cshtml

@@ -1,5 +1,4 @@
-@using Microsoft.AspNetCore.Blazor
-@using Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
+@using Microsoft.AspNetCore.Blazor.Browser.Services.Temporary
 @inject HttpClient Http
 
 <h1>Weather forecast</h1>

samples/StandaloneApp/Pages/_ViewImports.cshtml

@@ -1 +1 @@
-@(Layout<StandaloneApp.Shared.MainLayout>())
+@(Layout<MainLayout>())

samples/StandaloneApp/Shared/MainLayout.cshtml

@@ -1,5 +1,4 @@
-@using Microsoft.AspNetCore.Blazor.RenderTree
-@(Implements<Microsoft.AspNetCore.Blazor.Layouts.ILayoutComponent>())
+@(Implements<ILayoutComponent>())
 
 <div class='container-fluid'>
     <div class='row'>

samples/StandaloneApp/Shared/NavMenu.cshtml

@@ -1,5 +1,4 @@
-@using Microsoft.AspNetCore.Blazor.Routing
-<div class='main-nav'>
+<div class='main-nav'>
     <div class='navbar navbar-inverse'>
         <div class='navbar-header'>
             <button type='button' class='navbar-toggle' data-toggle='collapse' data-target='.navbar-collapse'>

samples/StandaloneApp/_ViewImports.cshtml

@@ -0,0 +1,5 @@
+@using Microsoft.AspNetCore.Blazor
+@using Microsoft.AspNetCore.Blazor.Layouts
+@using Microsoft.AspNetCore.Blazor.Routing
+@using StandaloneApp
+@using StandaloneApp.Shared

src/Microsoft.AspNetCore.Blazor.Razor.Extensions/ScopeStack.cs

@@ -15,7 +15,7 @@ namespace Microsoft.AspNetCore.Blazor.Razor
     /// </summary>
     internal class ScopeStack
     {
-        private const string _renderFragmentTypeName = "Microsoft.AspNetCore.Blazor.RenderTree.RenderFragment";
+        private const string _renderFragmentTypeName = "Microsoft.AspNetCore.Blazor.RenderFragment";
 
         private readonly Stack<ScopeEntry> _stack = new Stack<ScopeEntry>();
         private int _builderVarNumber = 1;

src/Microsoft.AspNetCore.Blazor/RenderFragment.cs

@@ -1,7 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-namespace Microsoft.AspNetCore.Blazor.RenderTree
+using Microsoft.AspNetCore.Blazor.RenderTree;
+
+namespace Microsoft.AspNetCore.Blazor
 {
     /// <summary>
     /// Represents a segment of UI content, implemented as a delegate that

src/Microsoft.AspNetCore.Blazor/UIEventArgs.cs

@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-namespace Microsoft.AspNetCore.Blazor.RenderTree
+namespace Microsoft.AspNetCore.Blazor
 {
     /// <summary>
     /// Supplies information about an event that is being raised.

src/Microsoft.AspNetCore.Blazor/UIEventHandler.cs

@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-namespace Microsoft.AspNetCore.Blazor.RenderTree
+namespace Microsoft.AspNetCore.Blazor
 {
     /// <summary>
     /// Handles an event raised for a <see cref="RenderTreeFrame"/>.

test/Microsoft.AspNetCore.Blazor.Build.Test/RazorCompilerTest.cs

@@ -265,7 +265,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
                 @functions {
                     public bool HandlerWasCalled { get; set; } = false;
 
-                    void MyHandleEvent(Microsoft.AspNetCore.Blazor.RenderTree.UIEventArgs eventArgs)
+                    void MyHandleEvent(Microsoft.AspNetCore.Blazor.UIEventArgs eventArgs)
                     {
                         HandlerWasCalled = true;
                     }

test/testapps/BasicTestApp/KeyPressEventComponent.cshtml

@@ -1,5 +1,5 @@
 @using System.Collections.Generic
-@using Microsoft.AspNetCore.Blazor.RenderTree
+@using Microsoft.AspNetCore.Blazor
 Type here: <input onkeypress=@OnKeyPressed />
 <ul>
     @foreach (var key in keysPressed)

test/testapps/BasicTestApp/RenderFragmentToggler.cshtml

@@ -1,4 +1,4 @@
-@using Microsoft.AspNetCore.Blazor.RenderTree
+@using Microsoft.AspNetCore.Blazor
 <div>
     <p>Fragment will be toggled below</p>