GN: build skiaserve

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 4501af15b2e24d6bb93798991a2a49514f3ff704..26a23be6c9e3d40e638b410611aaebf659b8d75b 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -920,4 +920,36 @@ if (skia_enable_tools) {
     ]
     testonly = true
   }
+
+  executable("skiaserve") {
+    sources = [
+      "tools/skiaserve/Request.cpp",
+      "tools/skiaserve/Response.cpp",
+      "tools/skiaserve/skiaserve.cpp",
+      "tools/skiaserve/urlhandlers/BatchBoundsHandler.cpp",
+      "tools/skiaserve/urlhandlers/BatchesHandler.cpp",
+      "tools/skiaserve/urlhandlers/BreakHandler.cpp",
+      "tools/skiaserve/urlhandlers/ClipAlphaHandler.cpp",
+      "tools/skiaserve/urlhandlers/CmdHandler.cpp",
+      "tools/skiaserve/urlhandlers/ColorModeHandler.cpp",
+      "tools/skiaserve/urlhandlers/DataHandler.cpp",
+      "tools/skiaserve/urlhandlers/DownloadHandler.cpp",
+      "tools/skiaserve/urlhandlers/EnableGPUHandler.cpp",
+      "tools/skiaserve/urlhandlers/ImgHandler.cpp",
+      "tools/skiaserve/urlhandlers/InfoHandler.cpp",
+      "tools/skiaserve/urlhandlers/PostHandler.cpp",
+      "tools/skiaserve/urlhandlers/QuitHandler.cpp",
+      "tools/skiaserve/urlhandlers/RootHandler.cpp",
+    ]
+    deps = [
+      ":flags",
+      ":gpu_tool_utils",
+      ":skia",
+      ":tool_utils",
+      "//third_party/jsoncpp",
+      "//third_party/libmicrohttpd",
+      "//third_party/libpng",
+    ]
+    testonly = true
+  }
 }