GN: fixes for Mac

 - Make fiddle build on Mac (skipping GL).
 - Now that we're building in SkCodec, we depend on libpng and libjpeg-turbo unconditionally, not just on Linux.
 - Re-arrange third_party a bit so that our targets are Fuchsia/Chrome compatible.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2184133002

NOTREECHECKS=true
This doesn't affect Chrome/Blink, so landing through the closed tree.

Review-Url: https://codereview.chromium.org/2184133002

6 files changed, 132 insertions, 120 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 1ddf12a957..07c70097af 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -19,7 +19,7 @@ skia_public_includes = [
   "include/utils",
   "include/utils/mac",
 
-  "include/c",   # TODO: move back to top, order shouldn't matter
+  "include/c",  # TODO: move back to top, order shouldn't matter
 ]
 
 # Skia public API, generally provided by :skia.
@@ -148,6 +148,8 @@ component("skia") {
     ":opts_avx",
     ":opts_sse41",
     ":opts_ssse3",
+    "//third_party/libjpeg_turbo",
+    "//third_party/libpng",
     "//third_party/zlib",
   ]
 
@@ -221,8 +223,6 @@ component("skia") {
     deps += [
       "third_party:fontconfig",
       "third_party:freetype2",
-      "third_party:libjpeg-turbo",
-      "third_party:libpng",
     ]
     sources += [
       "src/fonts/SkFontMgr_fontconfig.cpp",
@@ -262,7 +262,10 @@ action("skia.h") {
 
 executable("fiddle") {
   include_dirs = [ "$target_gen_dir" ]
-  libs = [ "OSMesa" ]
+  libs = []
+  if (is_linux) {
+    libs += [ "OSMesa" ]
+  }
 
   sources = [
     "tools/fiddle/draw.cpp",
diff --git a/gn/echo_headers.py b/gn/echo_headers.py
index 325124fc22..6fed8545be 100644
--- a/gn/echo_headers.py
+++ b/gn/echo_headers.py
@@ -11,6 +11,7 @@ import os.path
 
 blacklist = [
   'GrGLConfig_chrome.h',
+  'SkFontMgr_fontconfig.h',
 ]
 
 headers = []
diff --git a/third_party/BUILD.gn b/third_party/BUILD.gn
index 1aca3ca9cb..49d9f568c4 100644
--- a/third_party/BUILD.gn
+++ b/third_party/BUILD.gn
@@ -6,89 +6,6 @@
 declare_args() {
 }
 
-import("third_party.gni")
-
-config("libpng_public") {
-  include_dirs = [ "libpng" ]
-}
-third_party("libpng") {
-  public_configs = [ ":libpng_public" ]
-
-  deps = [
-    "//third_party/zlib",
-  ]
-  sources = [
-    "libpng/png.c",
-    "libpng/pngerror.c",
-    "libpng/pngget.c",
-    "libpng/pngmem.c",
-    "libpng/pngpread.c",
-    "libpng/pngread.c",
-    "libpng/pngrio.c",
-    "libpng/pngrtran.c",
-    "libpng/pngrutil.c",
-    "libpng/pngset.c",
-    "libpng/pngtrans.c",
-    "libpng/pngwio.c",
-    "libpng/pngwrite.c",
-    "libpng/pngwtran.c",
-    "libpng/pngwutil.c",
-  ]
-}
-
-config("libjpeg-turbo_config") {
-  include_dirs = [ "externals/libjpeg-turbo" ]
-}
-third_party("libjpeg-turbo") {
-  public_configs = [ ":libjpeg-turbo_config" ]
-
-  sources = [
-    "externals/libjpeg-turbo/jcapimin.c",
-    "externals/libjpeg-turbo/jcapistd.c",
-    "externals/libjpeg-turbo/jccoefct.c",
-    "externals/libjpeg-turbo/jccolor.c",
-    "externals/libjpeg-turbo/jcdctmgr.c",
-    "externals/libjpeg-turbo/jchuff.c",
-    "externals/libjpeg-turbo/jcinit.c",
-    "externals/libjpeg-turbo/jcmainct.c",
-    "externals/libjpeg-turbo/jcmarker.c",
-    "externals/libjpeg-turbo/jcmaster.c",
-    "externals/libjpeg-turbo/jcomapi.c",
-    "externals/libjpeg-turbo/jcparam.c",
-    "externals/libjpeg-turbo/jcphuff.c",
-    "externals/libjpeg-turbo/jcprepct.c",
-    "externals/libjpeg-turbo/jcsample.c",
-    "externals/libjpeg-turbo/jdapimin.c",
-    "externals/libjpeg-turbo/jdapistd.c",
-    "externals/libjpeg-turbo/jdcoefct.c",
-    "externals/libjpeg-turbo/jdcolor.c",
-    "externals/libjpeg-turbo/jddctmgr.c",
-    "externals/libjpeg-turbo/jdhuff.c",
-    "externals/libjpeg-turbo/jdinput.c",
-    "externals/libjpeg-turbo/jdmainct.c",
-    "externals/libjpeg-turbo/jdmarker.c",
-    "externals/libjpeg-turbo/jdmaster.c",
-    "externals/libjpeg-turbo/jdmerge.c",
-    "externals/libjpeg-turbo/jdphuff.c",
-    "externals/libjpeg-turbo/jdpostct.c",
-    "externals/libjpeg-turbo/jdsample.c",
-    "externals/libjpeg-turbo/jerror.c",
-    "externals/libjpeg-turbo/jfdctflt.c",
-    "externals/libjpeg-turbo/jfdctfst.c",
-    "externals/libjpeg-turbo/jfdctint.c",
-    "externals/libjpeg-turbo/jidctflt.c",
-    "externals/libjpeg-turbo/jidctfst.c",
-    "externals/libjpeg-turbo/jidctint.c",
-    "externals/libjpeg-turbo/jidctred.c",
-    "externals/libjpeg-turbo/jmemmgr.c",
-    "externals/libjpeg-turbo/jmemnobs.c",
-    "externals/libjpeg-turbo/jquant1.c",
-    "externals/libjpeg-turbo/jquant2.c",
-    "externals/libjpeg-turbo/jsimd_none.c",
-    "externals/libjpeg-turbo/jutils.c",
-  ]
-}
-
 config("system_freetype2") {
   include_dirs = [ "/usr/include/freetype2" ]
   libs = [ "freetype" ]
diff --git a/third_party/libjpeg_turbo/BUILD.gn b/third_party/libjpeg_turbo/BUILD.gn
new file mode 100644
index 0000000000..f03bca70d5
--- /dev/null
+++ b/third_party/libjpeg_turbo/BUILD.gn
@@ -0,0 +1,62 @@
+# Copyright 2016 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+declare_args() {
+}
+
+import("../third_party.gni")
+
+config("libjpeg_turbo_config") {
+  include_dirs = [ "../externals/libjpeg-turbo" ]
+}
+third_party("libjpeg_turbo") {
+  public_configs = [ ":libjpeg_turbo_config" ]
+
+  sources = [
+    "../externals/libjpeg-turbo/jcapimin.c",
+    "../externals/libjpeg-turbo/jcapistd.c",
+    "../externals/libjpeg-turbo/jccoefct.c",
+    "../externals/libjpeg-turbo/jccolor.c",
+    "../externals/libjpeg-turbo/jcdctmgr.c",
+    "../externals/libjpeg-turbo/jchuff.c",
+    "../externals/libjpeg-turbo/jcinit.c",
+    "../externals/libjpeg-turbo/jcmainct.c",
+    "../externals/libjpeg-turbo/jcmarker.c",
+    "../externals/libjpeg-turbo/jcmaster.c",
+    "../externals/libjpeg-turbo/jcomapi.c",
+    "../externals/libjpeg-turbo/jcparam.c",
+    "../externals/libjpeg-turbo/jcphuff.c",
+    "../externals/libjpeg-turbo/jcprepct.c",
+    "../externals/libjpeg-turbo/jcsample.c",
+    "../externals/libjpeg-turbo/jdapimin.c",
+    "../externals/libjpeg-turbo/jdapistd.c",
+    "../externals/libjpeg-turbo/jdcoefct.c",
+    "../externals/libjpeg-turbo/jdcolor.c",
+    "../externals/libjpeg-turbo/jddctmgr.c",
+    "../externals/libjpeg-turbo/jdhuff.c",
+    "../externals/libjpeg-turbo/jdinput.c",
+    "../externals/libjpeg-turbo/jdmainct.c",
+    "../externals/libjpeg-turbo/jdmarker.c",
+    "../externals/libjpeg-turbo/jdmaster.c",
+    "../externals/libjpeg-turbo/jdmerge.c",
+    "../externals/libjpeg-turbo/jdphuff.c",
+    "../externals/libjpeg-turbo/jdpostct.c",
+    "../externals/libjpeg-turbo/jdsample.c",
+    "../externals/libjpeg-turbo/jerror.c",
+    "../externals/libjpeg-turbo/jfdctflt.c",
+    "../externals/libjpeg-turbo/jfdctfst.c",
+    "../externals/libjpeg-turbo/jfdctint.c",
+    "../externals/libjpeg-turbo/jidctflt.c",
+    "../externals/libjpeg-turbo/jidctfst.c",
+    "../externals/libjpeg-turbo/jidctint.c",
+    "../externals/libjpeg-turbo/jidctred.c",
+    "../externals/libjpeg-turbo/jmemmgr.c",
+    "../externals/libjpeg-turbo/jmemnobs.c",
+    "../externals/libjpeg-turbo/jquant1.c",
+    "../externals/libjpeg-turbo/jquant2.c",
+    "../externals/libjpeg-turbo/jsimd_none.c",
+    "../externals/libjpeg-turbo/jutils.c",
+  ]
+}
diff --git a/third_party/libpng/BUILD.gn b/third_party/libpng/BUILD.gn
new file mode 100644
index 0000000000..fd80aad3b9
--- /dev/null
+++ b/third_party/libpng/BUILD.gn
@@ -0,0 +1,37 @@
+# Copyright 2016 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+declare_args() {
+}
+
+import("../third_party.gni")
+
+config("libpng_public") {
+  include_dirs = [ "." ]
+}
+third_party("libpng") {
+  public_configs = [ ":libpng_public" ]
+
+  deps = [
+    "//third_party/zlib",
+  ]
+  sources = [
+    "png.c",
+    "pngerror.c",
+    "pngget.c",
+    "pngmem.c",
+    "pngpread.c",
+    "pngread.c",
+    "pngrio.c",
+    "pngrtran.c",
+    "pngrutil.c",
+    "pngset.c",
+    "pngtrans.c",
+    "pngwio.c",
+    "pngwrite.c",
+    "pngwtran.c",
+    "pngwutil.c",
+  ]
+}
diff --git a/tools/fiddle/fiddle_main.cpp b/tools/fiddle/fiddle_main.cpp
index f6270daaa5..1c80c4416c 100644
--- a/tools/fiddle/fiddle_main.cpp
+++ b/tools/fiddle/fiddle_main.cpp
@@ -8,8 +8,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#include <GL/osmesa.h>
-
 #include "fiddle_main.h"
 
 // Globals externed in fiddle_main.h
@@ -63,33 +61,31 @@ static SkData* encode_snapshot(const sk_sp<SkSurface>& surface) {
     return img ? img->encode() : nullptr;
 }
 
-static OSMesaContext create_osmesa_context() {
-    OSMesaContext osMesaContext =
-        OSMesaCreateContextExt(OSMESA_BGRA, 0, 0, 0, nullptr);
-    if (osMesaContext != nullptr) {
-        static uint32_t buffer[16 * 16];
-        OSMesaMakeCurrent(osMesaContext, &buffer, GL_UNSIGNED_BYTE, 16, 16);
-    }
-    return osMesaContext;
-}
+#if defined(__linux)
+    #include <GL/osmesa.h>
+    static sk_sp<GrContext> create_grcontext() {
+        // We just leak the OSMesaContext... the process will die soon anyway.
+        if (OSMesaContext osMesaContext = OSMesaCreateContextExt(OSMESA_BGRA, 0, 0, 0, nullptr)) {
+            static uint32_t buffer[16 * 16];
+            OSMesaMakeCurrent(osMesaContext, &buffer, GL_UNSIGNED_BYTE, 16, 16);
+        }
 
-static sk_sp<GrContext> create_mesa_grcontext() {
-    if (nullptr == OSMesaGetCurrentContext()) {
-        return nullptr;
-    }
-    auto osmesa_get = [](void* ctx, const char name[]) {
-        SkASSERT(nullptr == ctx);
-        SkASSERT(OSMesaGetCurrentContext());
-        return OSMesaGetProcAddress(name);
-    };
-    sk_sp<const GrGLInterface> mesa(GrGLAssembleInterface(nullptr, osmesa_get));
-    if (!mesa) {
-        return nullptr;
+        auto osmesa_get = [](void* ctx, const char name[]) {
+            SkASSERT(nullptr == ctx);
+            SkASSERT(OSMesaGetCurrentContext());
+            return OSMesaGetProcAddress(name);
+        };
+        sk_sp<const GrGLInterface> mesa(GrGLAssembleInterface(nullptr, osmesa_get));
+        if (!mesa) {
+            return nullptr;
+        }
+        return sk_sp<GrContext>(GrContext::Create(
+                                        kOpenGL_GrBackend,
+                                        reinterpret_cast<intptr_t>(mesa.get())));
     }
-    return sk_sp<GrContext>(GrContext::Create(
-                                    kOpenGL_GrBackend,
-                                    reinterpret_cast<intptr_t>(mesa.get())));
-}
+#else
+    static sk_sp<GrContext> create_grcontext() { return nullptr; }
+#endif
 
 int main() {
     const DrawOptions options = GetDrawOptions();
@@ -117,10 +113,9 @@ int main() {
         rasterData.reset(encode_snapshot(rasterSurface));
     }
     if (options.gpu) {
-        OSMesaContext osMesaContext = create_osmesa_context();
-        auto grContext = create_mesa_grcontext();
+        auto grContext = create_grcontext();
         if (!grContext) {
-            fputs("Unable to get Mesa GrContext.\n", stderr);
+            fputs("Unable to get GrContext.\n", stderr);
         } else {
             auto surface = SkSurface::MakeRenderTarget(
                     grContext.get(),
@@ -134,9 +129,6 @@ int main() {
             draw(surface->getCanvas());
             gpuData.reset(encode_snapshot(surface));
         }
-        if (osMesaContext) {
-            OSMesaDestroyContext(osMesaContext);
-        }
     }
     if (options.pdf) {
         SkDynamicMemoryWStream pdfStream;