Reland "Integrate SIMD optimisations for zlib"

third_party/zlib/zlib.gyp

Index: third_party/zlib/zlib.gyp
diff --git a/third_party/zlib/zlib.gyp b/third_party/zlib/zlib.gyp
index aef41ac2bd969dedff9e8f44ec821e8dddc357fb..8c5ae44b9b99501f01003318bc74229b1e07b1df 100644
--- a/third_party/zlib/zlib.gyp
+++ b/third_party/zlib/zlib.gyp
@@ -5,6 +5,22 @@
 {
   'targets': [
     {
+      'target_name' : 'zlib_x86_simd',
+      'type': 'static_library',
+      'conditions': [
+        # See http://crbug.com/420616 gyp on mac & ios doesn't apply cflags
+        ['OS!="ios" and OS!="mac" and (target_arch=="ia32" or target_arch=="x64")', {
+          'cflags' : ["-msse2", "-msse4.2", "-mpclmul"],
+          'sources' : [ 'crc_folding.c',
+                        'fill_window_sse.c']
+        }, {
+          'sources' : [ 'simd_stub.c' ],
+        }], ['OS=="android"', {
+          'toolsets': ['target', 'host'],
+        }],
+      ],
+    },
+    {
       'target_name': 'zlib',
       'type': 'static_library',
       'sources': [
@@ -31,11 +47,15 @@
         'trees.c',
         'trees.h',
         'uncompr.c',
+        'x86.h',
         'zconf.h',
         'zlib.h',
         'zutil.c',
         'zutil.h',
       ],
+      'dependencies' : [
+        'zlib_x86_simd'
+      ],
       'include_dirs': [
         '.',
       ],
@@ -45,6 +65,9 @@
         ],
       },
       'conditions': [
+        ['OS!="ios" and OS!="mac" and (target_arch=="ia32" or target_arch=="x64")', {
+          'sources' : [ 'x86.c', ],
+        }],
         ['OS!="win"', {
           'product_name': 'chrome_zlib',
         }], ['OS=="android"', {