Remove gl::LinkResult.

Instead of returning a small struct from LinkProgram calls we use
angle::Result. Linking can have 3 cases:

- the link was successful -> angle::Result::Continue
- the link failed -> angle::Result::Incomplete
- there was an internal error -> angle::Result::Stop

Note that any unexpected Incomplete is still an error. Each function
that accepts Incomplete must check explicitly.

This is the last user of ErrorOrResult.

Bug: angleproject:2491
Change-Id: Idba23be27efe4b561720a4bdd8fe486b40779497
Reviewed-on: https://chromium-review.googlesource.com/c/1255645
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@google.com>
diff --git a/src/libANGLE/Context.cpp b/src/libANGLE/Context.cpp
index 58742c0..fa0edf9 100644
--- a/src/libANGLE/Context.cpp
+++ b/src/libANGLE/Context.cpp
@@ -5771,7 +5771,7 @@
     //      ProgramD3D.
     if (programObject->isInUse())
     {
-        programObject->resolveLink();
+        programObject->resolveLink(this);
         if (programObject->isLinked())
         {
             ANGLE_CONTEXT_TRY(mGLState.onProgramExecutableChange(this, programObject));
@@ -7781,7 +7781,7 @@
     Program *program = mState.mShaderPrograms->getProgram(handle);
     if (program)
     {
-        program->resolveLink();
+        program->resolveLink(this);
     }
     return program;
 }
@@ -7924,6 +7924,7 @@
     {
         GLenum code = error.getCode();
         mErrors.insert(code);
+
         if (code == GL_OUT_OF_MEMORY && mContext->getWorkarounds().loseContextOnOutOfMemory)
         {
             mContext->markContextLost();