Add Instant Trace Event for shader compilation in gpu which outputs shader text as attribute

src/gpu/gl/GrGLShaderBuilder.cpp

Index: src/gpu/gl/GrGLShaderBuilder.cpp
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index 764d482389a122415d10f340b0404bd7e39d3947..7d2152f3018e3bbf4f69287a49c264b20cb98516 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -767,6 +767,9 @@ static GrGLuint attach_shader(const GrGLContext& glCtx,
             return 0;
         }
     }
+
+    TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("skia.gpu"), "skia_gpu::GLShader",
+                         TRACE_EVENT_SCOPE_THREAD, "shader", TRACE_STR_COPY(shaderSrc.c_str()));
     if (c_PrintShaders) {
         GrPrintf(shaderSrc.c_str());
         GrPrintf("\n");