Gyp is dead. Long live gn.

Remove the gyp build.  The .gypi files were not renamed so that diff and
rebase would work on this change.  They will be renamed in a separate
change.

BUG=angleproject:1569

Change-Id: If8a217027633293664b820104f91a4ca5889b24e
Reviewed-on: https://chromium-review.googlesource.com/1187380
Commit-Queue: Frank Henigman <[email protected]>
Reviewed-by: Jamie Madill <[email protected]>
Reviewed-by: Yuly Novikov <[email protected]>

.gitignore

@@ -30,7 +30,6 @@
 /third_party/gles1_conform
 /third_party/glslang/src
 /third_party/googletest/src
-/third_party/gyp
 /third_party/libpng/src
 /third_party/llvm-build
 /third_party/spirv-headers/src
@@ -60,4 +59,3 @@ Release_Win32/
 Release_x64/
 TestResults.qpa
 tools/clang
-tools/gyp

.gn

@@ -28,12 +28,12 @@ check_targets = []
 # to force additional review for new uses of exec_script, which is strongly
 # discouraged except for gypi_to_gn calls.
 exec_script_whitelist = angle_dotfile_settings.exec_script_whitelist +
-                        build_dotfile_settings.exec_script_whitelist + [
+                        build_dotfile_settings.exec_script_whitelist +
+                        [
                           "//build/config/sysroot.gni",
                           "//build/config/win/BUILD.gn",
                           "//build/config/win/visual_studio_version.gni",
                           "//build/gn_helpers.py",
-                          "//build/gypi_to_gn.py",
                         ]
 
 default_args = {