Prefix internal names in GLSL output

Prefixing internal names will avoid clashes with user-defined names.
We use prefix webgl_angle_ so that the internal names are both
reserved in WebGL on one hand and clearly separated from hashed names
starting with just webgl_ on the other hand.

BUG=angleproject:1597
TEST=WebGL conformance tests

Change-Id: I7deef9c1a38105c8b57eda13c84eec13e515a91a
Reviewed-on: https://chromium-review.googlesource.com/406247
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
diff --git a/src/compiler/translator/OutputGLSLBase.h b/src/compiler/translator/OutputGLSLBase.h
index 79e102a..760d3c7 100644
--- a/src/compiler/translator/OutputGLSLBase.h
+++ b/src/compiler/translator/OutputGLSLBase.h
@@ -61,9 +61,9 @@
 
     // Return the original name if hash function pointer is NULL;
     // otherwise return the hashed name.
-    TString hashName(const TString &name);
+    TString hashName(const TName &name);
     // Same as hashName(), but without hashing built-in variables.
-    TString hashVariableName(const TString &name);
+    TString hashVariableName(const TName &name);
     // Same as hashName(), but without hashing built-in functions and with unmangling.
     TString hashFunctionNameIfNeeded(const TName &mangledName);
     // Used to translate function names for differences between ESSL and GLSL