skia: Add support for ANGLE on linux

gyp/common.gypi

Index: gyp/common.gypi
diff --git a/gyp/common.gypi b/gyp/common.gypi
index a3ce66e3621ff19052c50f1bfbd196225ff93fb2..c5a06654842738cf458e718cba5e6a372b278300 100644
--- a/gyp/common.gypi
+++ b/gyp/common.gypi
@@ -28,10 +28,10 @@
           'error': '<!(Cannot build with skia_os=<(skia_os) on OS=<(OS))',
         }],
         [ 'skia_mesa and skia_os not in ["mac", "linux"]', {
-          'error': '<!(skia_mesa=1 only supported with skia_os="mac" or "linux".)',
+          'error': '<!(skia_mesa=1 only supported with skia_os="mac" or "linux". )',
         }],
-        [ 'skia_angle and not skia_os == "win"', {
-          'error': '<!(skia_angle=1 only supported with skia_os="win".)',
+        [ 'skia_angle and not (skia_os == "win" or skia_os == "linux")', {
+          'error': '<!(skia_angle=1 only supported with skia_os="win" or skia_ok="linux".)',

[bsalomon, 2015/09/21 12:57:08]

skia_os?

         }],
         [ 'skia_os == "chromeos" and OS != "linux"', {
           'error': '<!(Skia ChromeOS build is only supported on Linux.)',