Move SkGLContext and some GrGLInterface implementations to skgputest module

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1815823002
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot

Committed: https://skia.googlesource.com/skia/+/fe3456cb006110d045b26ff3f8681b893a757b58

Review URL: https://codereview.chromium.org/1815823002
diff --git a/dm/DMSrcSink.h b/dm/DMSrcSink.h
index 1a56e81..3a35acf 100644
--- a/dm/DMSrcSink.h
+++ b/dm/DMSrcSink.h
@@ -232,7 +232,8 @@
 
 class GPUSink : public Sink {
 public:
-    GPUSink(GrContextFactory::GLContextType, GrContextFactory::GLContextOptions,
+    GPUSink(sk_gpu_test::GrContextFactory::GLContextType,
+            sk_gpu_test::GrContextFactory::GLContextOptions,
             int samples, bool diText, SkColorType colorType, SkColorProfileType profileType,
             bool threaded);
 
@@ -241,13 +242,13 @@
     const char* fileExtension() const override { return "png"; }
     SinkFlags flags() const override { return SinkFlags{ SinkFlags::kGPU, SinkFlags::kDirect }; }
 private:
-    GrContextFactory::GLContextType    fContextType;
-    GrContextFactory::GLContextOptions fContextOptions;
-    int                                fSampleCount;
-    bool                               fUseDIText;
-    SkColorType                        fColorType;
-    SkColorProfileType                 fProfileType;
-    bool                               fThreaded;
+    sk_gpu_test::GrContextFactory::GLContextType    fContextType;
+    sk_gpu_test::GrContextFactory::GLContextOptions fContextOptions;
+    int                                             fSampleCount;
+    bool                                            fUseDIText;
+    SkColorType                                     fColorType;
+    SkColorProfileType                              fProfileType;
+    bool                                            fThreaded;
 };
 
 class PDFSink : public Sink {