Resubmit - Use SSE2 block differ for chromoting

remoting/remoting.gyp

Index: remoting/remoting.gyp
diff --git a/remoting/remoting.gyp b/remoting/remoting.gyp
index f39ef6b10720302e8fbc7e02da9054e2c679639f..9b5239fcc82aba91d26fab01e4bd9bfef8857362 100644
--- a/remoting/remoting.gyp
+++ b/remoting/remoting.gyp
@@ -183,6 +183,7 @@
         'chromoting_base',
         'chromoting_jingle_glue',
         'chromoting_protocol',
+        'differ_block',
       ],
       'sources': [
         'host/access_verifier.cc',
@@ -197,8 +198,6 @@
         'host/chromoting_host_context.h',
         'host/differ.h',
         'host/differ.cc',
-        'host/differ_block.h',
-        'host/differ_block.cc',
         'host/screen_recorder.cc',
         'host/screen_recorder.h',
         'host/heartbeat_sender.cc',
@@ -421,6 +420,46 @@
     },  # end of target 'chromoting_protocol'
 
     {
+      'target_name': 'differ_block',
+      'type': '<(library)',
+      'include_dirs': [
+        '..',
+      ],
+      'dependencies': [
+        '../media/media.gyp:cpu_features',
+      ],
+      'conditions': [
+        [ 'target_arch == "ia32" or target_arch == "x64"', {
+          'dependencies': [
+            'differ_block_sse2',
+          ],
+        }],
+      ],
+      'sources': [
+        'host/differ_block.cc',
+        'host/differ_block.h',
+      ],
+    }, # end of target differ_block
+
+    {
+      'target_name': 'differ_block_sse2',
+      'type': '<(library)',
+      'include_dirs': [
+        '..',
+      ],
+      'conditions': [
+        [ 'OS == "linux" or OS == "freebsd" or OS == "openbsd"', {
+          'cflags': [
+            '-msse2',
+          ],
+        }],
+      ],
+      'sources': [
+        'host/differ_block_sse2.cc',
+      ],
+    }, # end of target differ_block_sse2
+
+    {
       'target_name': 'chromotocol_test_client',
       'type': 'executable',
       'dependencies': [