Update from https://crrev.com/317530

skia/BUILD.gn

 # Copyright (c) 2013 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/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
-if (cpu_arch == "arm") {
+if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 
 skia_support_gpu = !is_ios
 skia_support_pdf = !is_ios && (enable_basic_printing || enable_print_preview)
 
 # The list of Skia defines that are to be set for chromium.
 gypi_skia_defines =
     exec_script("//build/gypi_to_gn.py",
                 [
@@ skipping 152 matching lines @@
   if (is_mac) {
     include_dirs += [ "//third_party/skia/include/utils/ios" ]
   }
 
   defines = []
 
   if (component_mode == "shared_library") {
     defines += [ "SKIA_IMPLEMENTATION=1" ]
   }
 
-  if (cpu_arch == "arm") {
+  if (current_cpu == "arm") {
     if (arm_use_neon) {
       defines += [ "SK_ARM_HAS_NEON" ]
     }
     if (arm_optionally_use_neon) {
       defines += [ "SK_ARM_HAS_OPTIONAL_NEON" ]
     }
   }
 
   # Settings for text blitting, chosen to approximate the system browser.
   if (is_linux) {
@@ skipping 99 matching lines @@
     "ext/skia_utils_win.cc",
     "ext/skia_utils_win.h",
   ]
 
   # The skia gypi values are relative to the skia_dir, so we need to rebase.
   sources += gypi_skia_core.sources
   sources += gypi_skia_effects.sources
   sources += gypi_skia_utils.sources
   sources += gypi_values.skia_library_sources
 
-  if (cpu_arch == "arm") {
+  # This and skia_opts are really the same conceptual target so share headers.
+  allow_circular_includes_from = [ ":skia_opts" ]
+
+  if (current_cpu == "arm") {
     sources += [
       "//third_party/skia/src/core/SkUtilsArm.cpp",
       "//third_party/skia/src/core/SkUtilsArm.h",
     ]
   }
 
   # GPU
   if (skia_support_gpu) {
     sources += gypi_skia_gpu.skgpu_sources
     sources += gypi_skia_gpu.skgpu_null_gl_sources
@@ skipping 213 matching lines @@
     configs -= [ "//build/config/compiler:optimize" ]
     configs += [ "//build/config/compiler:optimize_max" ]
   }
 }
 
 # Separated out so it can be compiled with different flags for SSE.
 source_set("skia_opts") {
   cflags = []
   defines = []
 
-  if (cpu_arch == "x86" || cpu_arch == "x64") {
+  if (current_cpu == "x86" || current_cpu == "x64") {
     sources = gypi_skia_opts.sse2_sources + gypi_skia_opts.ssse3_sources +
               gypi_skia_opts.sse41_sources +
               [
                 # Chrome-specific.
                 "ext/convolver_SSE2.cc",
               ]
 
     if (is_linux || is_mac) {
       cflags += [ "-msse4.1" ]
     }
-  } else if (cpu_arch == "arm") {
+  } else if (current_cpu == "arm") {
     # The assembly uses the frame pointer register (r7 in Thumb/r11 in
     # ARM), the compiler doesn't like that.
     cflags += [ "-fomit-frame-pointer" ]
 
     if (arm_version >= 7) {
       sources = gypi_skia_opts.armv7_sources
       if (arm_use_neon || arm_optionally_use_neon) {
         sources += gypi_skia_opts.neon_sources
 
         # Root build config sets -mfpu=$arm_fpu, which we expect to be neon
         # when running this.
         if (!arm_use_neon) {
           configs -= [ "//build/config/compiler:compiler_arm_fpu" ]
           cflags += [ "-mfpu=neon" ]
         }
       }
     } else {
       sources = gypi_skia_opts.none_sourcees
     }
-  } else if (cpu_arch == "mipsel") {
+  } else if (current_cpu == "mipsel") {
     cflags += [ "-fomit-frame-pointer" ]
     sources = gypi_skia_opts.none_sources
   } else {
     assert(false, "Need to port cpu specific stuff from skia_library_opts.gyp")
   }
 
   if (is_android && !is_debug) {
     configs -= [ "//build/config/compiler:optimize" ]
     configs += [ "//build/config/compiler:optimize_max" ]
   }
@@ skipping 27 matching lines @@
   ]
 
   if (!is_win && !is_mac) {
     sources -= [ "ext/platform_canvas_unittest.cc" ]
   }
 
   deps = [
     ":skia",
     "//base",
     "//base/test:run_all_unittests",
+    "//cc:test_support",  # TODO: Fix this test to not depend on cc.
     "//testing/gtest",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 }