Convert GrGLDriver/Vendor/Renderer to enum classes

Reformat uses to de-yodaify and try to improve readabilty of
complicated conditionals.

Change-Id: Ifccb84836cbe4f5a01813795ceb287089984f8ae
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/405685
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/tests/ProgramsTest.cpp b/tests/ProgramsTest.cpp
index 98cf7d9..68dbd8e 100644
--- a/tests/ProgramsTest.cpp
+++ b/tests/ProgramsTest.cpp
@@ -342,9 +342,9 @@
         // Android devices. We have passes on ARM devices with the default number of stages.
         // TODO When we run ES 3.00 GLSL in more places, test again
 #ifdef SK_BUILD_FOR_ANDROID
-            if (kARM_GrGLVendor != gpu->ctxInfo().vendor()) {
-                maxStages = 1;
-            }
+        if (gpu->ctxInfo().vendor() != GrGLVendor::kARM) {
+            maxStages = 1;
+        }
 #endif
         // On iOS we can exceed the maximum number of varyings. http://skbug.com/6627.
 #ifdef SK_BUILD_FOR_IOS
@@ -377,7 +377,7 @@
         GrGLGpu* gpu = static_cast<GrGLGpu*>(ctxInfo.directContext()->priv().getGpu());
         // Tecno Spark 3 Pro with Power VR Rogue GE8300 will fail shader compiles with
         // no message if the shader is particularly long.
-        if (gpu->ctxInfo().vendor() == kImagination_GrGLVendor) {
+        if (gpu->ctxInfo().vendor() == GrGLVendor::kImagination) {
             maxTreeLevels = 3;
         }
 #endif