Remove GL image support from SkSL

This was added to Ganesh briefly in 2016 for an experiment, then
reverted, and never used.

Change-Id: I65849aff53acc14f9adc7585398fd09363a4ed65
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374376
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/sksl/SkSLParser.cpp b/src/sksl/SkSLParser.cpp
index 832546d..418340f 100644
--- a/src/sksl/SkSLParser.cpp
+++ b/src/sksl/SkSLParser.cpp
@@ -892,7 +892,6 @@
     int set = -1;
     int builtin = -1;
     int inputAttachmentIndex = -1;
-    Layout::Format format = Layout::Format::kUnspecified;
     Layout::Primitive primitive = Layout::kUnspecified_Primitive;
     int maxVertices = -1;
     int invocations = -1;
@@ -903,8 +902,8 @@
     if (this->checkNext(Token::Kind::TK_LAYOUT)) {
         if (!this->expect(Token::Kind::TK_LPAREN, "'('")) {
             return Layout(flags, location, offset, binding, index, set, builtin,
-                          inputAttachmentIndex, format, primitive, maxVertices, invocations, marker,
-                          when, key, ctype);
+                          inputAttachmentIndex, primitive, maxVertices, invocations, marker, when,
+                          key, ctype);
         }
         for (;;) {
             Token t = this->nextToken();
@@ -994,8 +993,6 @@
                         this->error(t, ("'" + text + "' is not a valid layout qualifier").c_str());
                         break;
                 }
-            } else if (Layout::ReadFormat(text, &format)) {
-               // AST::ReadFormat stored the result in 'format'.
             } else {
                 this->error(t, ("'" + text + "' is not a valid layout qualifier").c_str());
             }
@@ -1008,7 +1005,7 @@
         }
     }
     return Layout(flags, location, offset, binding, index, set, builtin, inputAttachmentIndex,
-                  format, primitive, maxVertices, invocations, marker, when, key, ctype);
+                  primitive, maxVertices, invocations, marker, when, key, ctype);
 }
 
 /* layout? (UNIFORM | CONST | IN | OUT | INOUT | LOWP | MEDIUMP | HIGHP | FLAT | NOPERSPECTIVE |