Implement main blink target in GN.

Source/platform/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/ui.gni")
 import("//third_party/WebKit/Source/build/scripts/scripts.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//third_party/WebKit/Source/platform/platform_generated.gni")
 
+# Most targets in this file are private actions so use that as the default.
+visibility = ":*"
+
 # TODO(GYP) Remove when test targets link (depends on ffmpeg)
 enable_blink_platform_test_targets = false
 
 
 import("//third_party/yasm/yasm_assemble.gni")
 
 platform_gypi = exec_script(
     "//build/gypi_to_gn.py",
     [ rebase_path("blink_platform.gypi") ],
     "scope",
     [ "blink_platform.gypi" ])
 if (enable_blink_platform_test_targets) {
 heap_gypi = exec_script(
     "//build/gypi_to_gn.py",
     [ rebase_path("heap/blink_heap.gypi") ],
     "scope",
     [ "heap/blink_heap.gypi" ])
 }
 
 blink_platform_neon_files = [
   "graphics/cpu/arm/WebGLImageConversionNEON.h",
   "graphics/cpu/arm/filters/FEBlendNEON.h",
   "graphics/cpu/arm/filters/FECompositeArithmeticNEON.h",
   "graphics/cpu/arm/filters/FEGaussianBlurNEON.h",
   "graphics/cpu/arm/filters/NEONHelpers.h",
 ]
 
 # blink_common in blink_platform.gyp
 component("blink_common") {
+  visibility = "//third_party/WebKit/*"
   sources = [
     "exported/WebCString.cpp",
     "exported/WebString.cpp",
     "exported/WebCommon.cpp",
   ]
 
   defines = [
     "BLINK_COMMON_IMPLEMENTATION=1",
     "INSIDE_BLINK",
   ]
@@ skipping 101 matching lines @@
     "--key-positions=*",
     "-D", "-s", "2",
     rebase_path(color_data_gperf, root_build_dir),
     "--output-file=" + rebase_path(output_file, root_build_dir),
   ]
 }
 
 # This isn't strictly necessary since we can just add the deps to "platform",
 # but it helps to have the targets match the GYP build.
 group("make_platform_generated") {
+  visibility = "//third_party/WebKit/Source/*"
   deps = [
     ":blink_common",
     ":color_data",
     ":font_family_names",
     ":runtime_enabled_features",
   ]
 }
 
 # TODO(brettw) Objective C Renaming postbuild steps on Mac.
 # blink_platform target in blink_platform.gyp
 component("platform") {
+  visibility = "//third_party/WebKit/*"
   output_name = "blink_platform"
 
   sources = platform_gypi.platform_files
   sources -= blink_platform_neon_files
 
   # Add in the generated files.
   sources +=
     get_target_outputs(":font_family_names") +
     get_target_outputs(":runtime_enabled_features") +
     get_target_outputs(":color_data")
@@ skipping 152 matching lines @@
     # TODO(GYP)
     #deps += [ "//third_party/ffmpeg" ]
   }
   if (use_openmax_dl_fft) {
     include_dirs += [ "//third_party/openmax_dl" ]
     # TODO(GYP)
     # deps += [ "//third_party/openmax_dl/dl" ]
   }
 }
 
-
 yasm_assemble("heap_asm_stubs") {
   if (cpu_arch == "x86" || cpu_arch == "x64") {
     sources = [ "heap/asm/SaveRegisters_x86.asm" ]
   } else if (cpu_arch == "arm") {
     sources = [ "heap/asm/SaveRegisters_arm.S" ]
   } else if (cpu_arch == "arm64") {
     sources = [ "heap/asm/SaveRegisters_arm64.S" ]
   } else if (cpu_arch == "mipsel") {
     sources = [ "heap/asm/SaveRegisters_mips.S" ]
   }
@@ skipping 128 matching lines @@
     #'cflags': ['-marm'],
     #    'conditions': [
     #      ['OS=="android"', {
     #        'cflags!': ['-mthumb'],
     #      }],
     #    ],
 
     deps = [ ":blink_common" ]
   }
 }