Move OpenGL specific details behind renderPipeline interface.

Test: new and existing unit tests still pass.
Change-Id: I6164f30f45ebe450788ed8d949eca5af9a44e585
diff --git a/libs/hwui/Android.mk b/libs/hwui/Android.mk
index 5069a9a..a9bd75c 100644
--- a/libs/hwui/Android.mk
+++ b/libs/hwui/Android.mk
@@ -266,6 +266,7 @@
     tests/unit/BakedOpDispatcherTests.cpp \
     tests/unit/BakedOpRendererTests.cpp \
     tests/unit/BakedOpStateTests.cpp \
+    tests/unit/CanvasContextTests.cpp \
     tests/unit/CanvasStateTests.cpp \
     tests/unit/ClipAreaTests.cpp \
     tests/unit/DamageAccumulatorTests.cpp \