Update Chomium's build files to work w/ latest GN binaries.

skia/BUILD.gn

Index: skia/BUILD.gn
diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index e55730f8d486373dd6546f1c1c62fc3295f88244..616333eb495f454f318be5364c34a44d7e9f435a 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -5,7 +5,7 @@
 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")
 }
 
@@ -220,7 +220,7 @@ config("skia_library_config") {
     defines += [ "SKIA_IMPLEMENTATION=1" ]
   }
 
-  if (cpu_arch == "arm") {
+  if (current_cpu == "arm") {
     if (arm_use_neon) {
       defines += [ "SK_ARM_HAS_NEON" ]
     }
@@ -340,7 +340,7 @@ component("skia") {
   sources += gypi_skia_utils.sources
   sources += gypi_values.skia_library_sources
 
-  if (cpu_arch == "arm") {
+  if (current_cpu == "arm") {
     sources += [
       "//third_party/skia/src/core/SkUtilsArm.cpp",
       "//third_party/skia/src/core/SkUtilsArm.h",
@@ -574,7 +574,7 @@ 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 +
               [
@@ -585,7 +585,7 @@ source_set("skia_opts") {
     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" ]
@@ -605,7 +605,7 @@ source_set("skia_opts") {
     } 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 {