Move GL headers from gpu to third_party/khronos

gpu/gpu.gyp

Index: gpu/gpu.gyp
diff --git a/gpu/gpu.gyp b/gpu/gpu.gyp
index ab5650a2b517c6b05f18e8edb1086645ec4217a8..adbc24112d8f32eabda63d2064c14b11fc1ffe73 100644
--- a/gpu/gpu.gyp
+++ b/gpu/gpu.gyp
@@ -30,11 +30,11 @@
       'target_name': 'command_buffer_common',
       'type': 'static_library',
       'include_dirs': [
-        '.',
+        '<(DEPTH)/third_party/khronos',
       ],
       'all_dependent_settings': {
         'include_dirs': [
-          '.',
+          '<(DEPTH)/third_party/khronos',
         ],
       },
       'dependencies': [
@@ -90,7 +90,7 @@
       'all_dependent_settings': {
         'include_dirs': [
           # For GLES2/gl2.h
-          '.',
+          '<(DEPTH)/third_party/khronos',
         ],
       },
       'sources': [
@@ -112,7 +112,7 @@
       'all_dependent_settings': {
         'include_dirs': [
           # For GLES2/gl2.h
-          '.',
+          '<(DEPTH)/third_party/khronos',
         ],
       },
       'sources': [
@@ -152,10 +152,12 @@
       'type': 'static_library',
       'include_dirs': [
         '..',
+        '<(DEPTH)/third_party/khronos',
       ],
       'all_dependent_settings': {
         'include_dirs': [
           '..',
+          '<(DEPTH)/third_party/khronos',
         ],
       },
       'dependencies': [
@@ -177,10 +179,12 @@
       'type': 'static_library',
       'include_dirs': [
         '..',
+        '<(DEPTH)/third_party/khronos',
       ],
       'all_dependent_settings': {
         'include_dirs': [
           '..',
+          '<(DEPTH)/third_party/khronos',
         ],
       },
       'dependencies': [
@@ -327,6 +331,7 @@
       ],
       'include_dirs': [
         '..',
+        '<(DEPTH)/third_party/khronos',
       ],
       'sources': [
         'command_buffer/common/gl_mock.h',
@@ -345,6 +350,7 @@
       ],
       'include_dirs': [
         '..',
+        '<(DEPTH)/third_party/khronos',
       ],
       'sources': [
         'ipc/gpu_command_buffer_traits.cc',