Revert of Move SkGLContext and some GrGLInterface implementations to skgputest module

gyp/gpu.gyp

Index: gyp/gpu.gyp
diff --git a/gyp/gpu.gyp b/gyp/gpu.gyp
index 2fedbed93c058d05fa75f8188b245ddaf1fe3357..80fc932b8ab2065164a25ab3c023f9b02eb2449b 100644
--- a/gyp/gpu.gyp
+++ b/gyp/gpu.gyp
@@ -102,6 +102,11 @@
       'sources': [
         '<@(skgpu_sources)',
         '<@(skgpu_native_gl_sources)',
+        '<@(skgpu_angle_gl_sources)',
+        '<@(skgpu_command_buffer_gl_sources)',
+        '<@(skgpu_mesa_gl_sources)',
+        '<@(skgpu_debug_gl_sources)',
+        '<@(skgpu_null_gl_sources)',
         '<@(skgpu_vk_sources)',
         'gpu.gypi', # Makes the gypi appear in IDEs (but does not modify the build).
       ],
@@ -146,6 +151,23 @@
             ],
           },
         }],
+        [ 'skia_egl == 1', {
+          'defines': [
+            'SK_EGL=1',
+          ],
+        }],
+        [ 'skia_egl == 0', {
+          'defines': [
+            'SK_EGL=0',
+          ],
+        }],
+        [ 'skia_mesa and skia_os == "linux"', {
+          'link_settings': {
+            'libraries': [
+              '-lOSMesa',
+            ],
+          },
+        }],
         [ 'skia_os == "mac"', {
           'link_settings': {
             'libraries': [
@@ -157,10 +179,44 @@
             '../src/gpu/gl/GrGLCreateNativeInterface_none.cpp',
           ],
         }],
+        [ 'not skia_mesa', {
+          'sources!': [
+            '../src/gpu/gl/mesa/SkMesaGLContext.cpp',
+            '../src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp',
+          ],
+        }],
+        [ 'skia_mesa and skia_os == "mac"', {
+          'link_settings': {
+            'libraries': [
+              '/opt/X11/lib/libOSMesa.dylib',
+            ],
+          },
+          'include_dirs': [
+             '/opt/X11/include/',
+          ],
+        }],
         [ 'skia_os in ["win", "ios"]', {
           'sources!': [
             '../src/gpu/gl/GrGLDefaultInterface_none.cpp',
             '../src/gpu/gl/GrGLCreateNativeInterface_none.cpp',
+          ],
+        }],
+        [ 'skia_angle', {
+          'dependencies': [
+            'angle.gyp:*',
+          ],
+          'export_dependent_settings': [
+            'angle.gyp:*',
+          ],
+        }, { # not skia_angle
+          'sources!': [
+            '<@(skgpu_angle_gl_sources)',
+          ],
+        }],
+        [ 'skia_command_buffer', {
+        }, { # not skia_command_buffer
+          'sources!': [
+            '<@(skgpu_command_buffer_gl_sources)',
           ],
         }],
         [ 'skia_os == "android"', {