Add sw support to viewer on Linux.

tools/viewer/sk_app/unix/Window_unix.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 //#include <tchar.h>
 
 #include "WindowContextFactory_unix.h"
@@ skipping 29 matching lines @@
                         KeyPressMask | KeyReleaseMask | 
                         PointerMotionMask | ButtonPressMask | ButtonReleaseMask;
 
 bool Window_unix::initWindow(Display* display, const DisplayParams* params) {
     if (params && params->fMSAASampleCount != fMSAASampleCount) {
         this->closeWindow();
     }
     // we already have a window
     if (fDisplay) {
         return true;
-    } 
+    }
     fDisplay = display;
 
     fWidth = 1280;
     fHeight = 960;
 
     // Attempt to create a window that supports GL
     GLint att[] = {
         GLX_RGBA,
         GLX_DEPTH_SIZE, 24,
         GLX_DOUBLEBUFFER,
@@ skipping 204 matching lines @@
     XSetWMName(fDisplay, fWindow, &textproperty);    
 }
 
 void Window_unix::show() {
     XMapWindow(fDisplay, fWindow);
 }
 
 bool Window_unix::attach(BackendType attachType, const DisplayParams& params) {
     this->initWindow(fDisplay, &params);
 
-    window_context_factory::XlibWindowInfo xwinInfo;
-    xwinInfo.fDisplay = fDisplay;
-    xwinInfo.fWindow = fWindow;
-    xwinInfo.fVisualInfo = fVisualInfo;
+    window_context_factory::XlibWindowInfo winInfo;
+    winInfo.fDisplay = fDisplay;
+    winInfo.fWindow = fWindow;
+    winInfo.fVisualInfo = fVisualInfo;
     switch (attachType) {
 #ifdef SK_VULKAN
         case kVulkan_BackendType:
-            fWindowContext = window_context_factory::NewVulkanForXlib(xwinInfo, params);
+            fWindowContext = window_context_factory::NewVulkanForXlib(winInfo, params);
             break;
 #endif
         case kNativeGL_BackendType:
-        default:
-            fWindowContext = window_context_factory::NewGLForXlib(xwinInfo, params);
+            fWindowContext = window_context_factory::NewGLForXlib(winInfo, params);
+            break;
+        case kRaster_BackendType:
+            fWindowContext = window_context_factory::NewRasterForXlib(winInfo, params);
             break;
     }
 
     return (SkToBool(fWindowContext));
 }
 
 void Window_unix::onInval() {
     XEvent event;
     event.type = Expose;
     event.xexpose.send_event = True;
     event.xexpose.display = fDisplay;
     event.xexpose.window = fWindow;
     event.xexpose.x = 0;
     event.xexpose.y = 0;
     event.xexpose.width = fWidth;
     event.xexpose.height = fHeight;
     event.xexpose.count = 0;
     
     XSendEvent(fDisplay, fWindow, False, 0, &event);
 }
 
 }   // namespace sk_app