Rationalize dependency on khronos EGL headers in place of angle.

content/content_common.gypi

Index: content/content_common.gypi
diff --git a/content/content_common.gypi b/content/content_common.gypi
index e0558e980772b5203f0a1b9191d5ed01d07c02c6..b80755e22b2c5db4c281b27fa91d7a13817fb701 100644
--- a/content/content_common.gypi
+++ b/content/content_common.gypi
@@ -452,7 +452,7 @@
     }],
     ['use_x11 == 1', {
       'include_dirs': [
-        '<(DEPTH)/third_party/angle/include',
+        '<(DEPTH)/third_party/khronos',
       ],
       'link_settings': {
         'libraries': [
@@ -503,7 +503,7 @@
         'common/gpu/media/omx_video_decode_accelerator.h',
       ],
       'include_dirs': [
-        '<(DEPTH)/third_party/angle/include',
+        '<(DEPTH)/third_party/khronos',
         '<(DEPTH)/third_party/openmax/il',
       ],
       'link_settings': {
@@ -556,7 +556,7 @@
         'common/gpu/media/dxva_video_decode_accelerator.h',
       ],
       'include_dirs': [
-        '<(DEPTH)/third_party/angle/include',
+        '<(DEPTH)/third_party/khronos',
       ],
     }],
     ['OS=="win" and directxsdk_exists=="True"', {