command_buffer_gles2: Implement EGL default Display as a global object

gpu/BUILD.gn

Index: gpu/BUILD.gn
diff --git a/gpu/BUILD.gn b/gpu/BUILD.gn
index 63099d3beaebb0b2d62fb5d09f6928157a04c213..608e4b7759abd5e1d4477cd77c8025893e2d336d 100644
--- a/gpu/BUILD.gn
+++ b/gpu/BUILD.gn
@@ -57,6 +57,8 @@ shared_library("command_buffer_gles2") {
     # TODO(hendrikw): Move egl out of gles2_conform_support.
     "gles2_conform_support/egl/config.cc",
     "gles2_conform_support/egl/config.h",
+    "gles2_conform_support/egl/context.cc",
+    "gles2_conform_support/egl/context.h",
     "gles2_conform_support/egl/display.cc",
     "gles2_conform_support/egl/display.h",
     "gles2_conform_support/egl/egl.cc",
@@ -64,6 +66,8 @@ shared_library("command_buffer_gles2") {
     "gles2_conform_support/egl/surface.h",
     "gles2_conform_support/egl/test_support.cc",
     "gles2_conform_support/egl/test_support.h",
+    "gles2_conform_support/egl/thread_state.cc",
+    "gles2_conform_support/egl/thread_state.h",
   ]
 
   deps = [
@@ -71,6 +75,7 @@ shared_library("command_buffer_gles2") {
     "//base",
     "//gpu/command_buffer/client:gles2_c_lib",
     "//gpu/command_buffer/client:gles2_implementation",
+    "//gpu/command_buffer/common:gles2_utils",
     "//ui/gl:gl",
   ]