Add macro to decide GrGLStandard

This allows us to remove certain interfaces at compile time.

This replaces most (all?) of the cases where it was
if (gl) else [implicit gles] to be explicitly
if (gl) else if (gles)
in preparation for adding a WebGL standard.

For consistency, I tried to check first for GL, then for
GLES, which involved re-arranging a few if blocks.

PS 3 removes about 1.2KB (0.4 KB gzipped) from CanvasKit by
removing the GrGLInterface related checks from
GrGlInterface::validate()

PS 8 removes a total of 6.0 KB (2.6 KB gzipped) from
GrGlInterface::validate() and GrGlCaps::*

Bug: skia:8378
Change-Id: Ia91b732d888907f5d94b0eac8ca023084999fa7e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/201604
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/src/gpu/gl/GrGLGLSL.cpp b/src/gpu/gl/GrGLGLSL.cpp
index 4050d36..02dcc3f 100644
--- a/src/gpu/gl/GrGLGLSL.cpp
+++ b/src/gpu/gl/GrGLGLSL.cpp
@@ -14,39 +14,37 @@
     if (GR_GLSL_INVALID_VER == ver) {
         return false;
     }
-    switch (gl->fStandard) {
-        case kGL_GrGLStandard:
-            SkASSERT(ver >= GR_GLSL_VER(1,10));
-            if (ver >= GR_GLSL_VER(4,20)) {
-                *generation = k420_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(4,00)) {
-                *generation = k400_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(3,30)) {
-                *generation = k330_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(1,50)) {
-                *generation = k150_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(1,40)) {
-                *generation = k140_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(1,30)) {
-                *generation = k130_GrGLSLGeneration;
-            } else {
-                *generation = k110_GrGLSLGeneration;
-            }
-            return true;
-        case kGLES_GrGLStandard:
-            SkASSERT(ver >= GR_GL_VER(1,00));
-            if (ver >= GR_GLSL_VER(3,20)) {
-                *generation = k320es_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(3,10)) {
-                *generation = k310es_GrGLSLGeneration;
-            } else if (ver >= GR_GLSL_VER(3,00)) {
-                *generation = k330_GrGLSLGeneration;
-            } else {
-                *generation = k110_GrGLSLGeneration;
-            }
-            return true;
-        default:
-            SK_ABORT("Unknown GL Standard");
-            return false;
+    if (GR_IS_GR_GL(gl->fStandard)) {
+        SkASSERT(ver >= GR_GLSL_VER(1,10));
+        if (ver >= GR_GLSL_VER(4,20)) {
+            *generation = k420_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(4,00)) {
+            *generation = k400_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(3,30)) {
+            *generation = k330_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(1,50)) {
+            *generation = k150_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(1,40)) {
+            *generation = k140_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(1,30)) {
+            *generation = k130_GrGLSLGeneration;
+        } else {
+            *generation = k110_GrGLSLGeneration;
+        }
+        return true;
+    } else if (GR_IS_GR_GL_ES(gl->fStandard)) {
+        SkASSERT(ver >= GR_GL_VER(1,00));
+        if (ver >= GR_GLSL_VER(3,20)) {
+            *generation = k320es_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(3,10)) {
+            *generation = k310es_GrGLSLGeneration;
+        } else if (ver >= GR_GLSL_VER(3,00)) {
+            *generation = k330_GrGLSLGeneration;
+        } else {
+            *generation = k110_GrGLSLGeneration;
+        }
+        return true;
     }
+    SK_ABORT("Unknown GL Standard");
+    return false;
 }