Added transform feedback shader generation.

BUG=angle:495

Change-Id: I41a0177fd3eb43c9f4ab9e54faeadac3eb483c2c
Reviewed-on: https://chromium-review.googlesource.com/185035
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libGLESv2/Context.cpp b/src/libGLESv2/Context.cpp
index 5a47b5a..bddab35 100644
--- a/src/libGLESv2/Context.cpp
+++ b/src/libGLESv2/Context.cpp
@@ -1065,12 +1065,12 @@
     return mResourceManager->getBuffer(handle);
 }
 
-Shader *Context::getShader(GLuint handle)
+Shader *Context::getShader(GLuint handle) const
 {
     return mResourceManager->getShader(handle);
 }
 
-Program *Context::getProgram(GLuint handle)
+Program *Context::getProgram(GLuint handle) const
 {
     return mResourceManager->getProgram(handle);
 }