Reland: Add ETC1 powered SSE encoder for tile texture compression

cc/cc.gyp

Index: cc/cc.gyp
diff --git a/cc/cc.gyp b/cc/cc.gyp
index aeea01861d2ddf3def9fef729e6beab473b21f60..764a3e74c220bdb46a11d86abb3919a70d96f58d 100644
--- a/cc/cc.gyp
+++ b/cc/cc.gyp
@@ -20,6 +20,7 @@
         '<(DEPTH)/ui/events/events.gyp:events_base',
         '<(DEPTH)/ui/gfx/gfx.gyp:gfx',
         '<(DEPTH)/ui/gfx/gfx.gyp:gfx_geometry',
+        'cc_opts',
       ],
       'variables': {
         'optimize': 'max',
@@ -630,5 +631,41 @@
         '../build/android/increase_size_for_speed.gypi',
       ],
     },
+    {
+      'target_name': 'cc_opts',

[reveman, 2015/05/06 18:44:00]

hm, do we really need a separate target for this? I assume we're doing something
similar somewhere else that this is based on. Can you point to that code?

[radu.velea, 2015/05/07 11:21:38]

I got the idea from https://codereview.chromium.org/793693003/
I expect we will have a similar NEON module in the near future.

+      'type': 'static_library',
+      'conditions': [
+        ['target_arch == "ia32" or target_arch == "x64"', {
+          'defines': [
+            'CC_IMPLEMENTATION=1',
+          ],
+          'dependencies': [
+            'cc_opts_sse',
+          ]          
+        }],
+      ],  
+    },    
+    {
+      'target_name': 'cc_opts_sse',
+      'type': 'static_library',
+      'dependencies': [
+        '<(DEPTH)/base/base.gyp:base',
+      ],
+      'conditions': [
+        ['target_arch == "ia32" or target_arch == "x64"', {
+          'defines': [
+            'CC_IMPLEMENTATION=1',
+          ],
+          'sources': [
+            # Conditional compilation for SSE2 code on x86 and x64 machines
+            'resources/texture_compressor_etc1_sse.cc',
+            'resources/texture_compressor_etc1_sse.h',
+          ],
+          'cflags': [
+            '-msse2',

[reveman, 2015/05/06 18:44:00]

is this not needed in the gn build case too?

[radu.velea, 2015/05/07 11:21:38]

It seems to compile without it. I'm not sure who sets msse2 flag. I've done a
"grep" and noticed:
./build/common.gypi:                # -mfpmath=sse -msse2 makes the compiler use
SSE instructions
./build/common.gypi:                  '-msse2', 
./cc/cc.gyp:            '-msse2',
./media/media.gyp:            '-msse2',
./media/base/BUILD.gn:      cflags = [ "-msse2" ]

I've added it in Build.gn.

+          ],
+        }],
+      ],
+    },    
   ],
 }