Add class GrGLTextureRenderTarget for GL texture/rendertarget objects

gyp/gpu.gypi

 # Include this gypi to include all 'gpu' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
 #
 {
   'variables': {
     'skgpu_sources': [
@@ skipping 229 matching lines @@
       '<(skia_src_path)/gpu/gl/GrGLRenderTarget.cpp',
       '<(skia_src_path)/gpu/gl/GrGLRenderTarget.h',
       '<(skia_src_path)/gpu/gl/GrGLShaderVar.h',
       '<(skia_src_path)/gpu/gl/GrGLSL.cpp',
       '<(skia_src_path)/gpu/gl/GrGLSL.h',
       '<(skia_src_path)/gpu/gl/GrGLSL_impl.h',
       '<(skia_src_path)/gpu/gl/GrGLStencilBuffer.cpp',
       '<(skia_src_path)/gpu/gl/GrGLStencilBuffer.h',
       '<(skia_src_path)/gpu/gl/GrGLTexture.cpp',
       '<(skia_src_path)/gpu/gl/GrGLTexture.h',
+      '<(skia_src_path)/gpu/gl/GrGLTextureRenderTarget.h',
       '<(skia_src_path)/gpu/gl/GrGLUtil.cpp',
       '<(skia_src_path)/gpu/gl/GrGLUtil.h',
       '<(skia_src_path)/gpu/gl/GrGLUniformHandle.h',
       '<(skia_src_path)/gpu/gl/GrGLVertexArray.cpp',
       '<(skia_src_path)/gpu/gl/GrGLVertexArray.h',
       '<(skia_src_path)/gpu/gl/GrGLVertexBuffer.cpp',
       '<(skia_src_path)/gpu/gl/GrGLVertexBuffer.h',
       '<(skia_src_path)/gpu/gl/GrGpuGL.cpp',
       '<(skia_src_path)/gpu/gl/GrGpuGL.h',
       '<(skia_src_path)/gpu/gl/GrGpuGL_program.cpp',
@@ skipping 93 matching lines @@
     ],
     'skgpu_null_gl_sources': [
       '<(skia_src_path)/gpu/gl/GrGLCreateNullInterface.cpp',
 
       # Sk files
       '<(skia_include_path)/gpu/gl/SkNullGLContext.h',
       '<(skia_src_path)/gpu/gl/SkNullGLContext.cpp',
     ],
   },
 }