Enable partial invalidates when rendering with OpenGL.

Change-Id: Ie8be06c4776b815e8737753eb8003b4fd8936130
diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
index 1c89577..36709dc 100644
--- a/libs/hwui/LayerRenderer.cpp
+++ b/libs/hwui/LayerRenderer.cpp
@@ -26,7 +26,7 @@
 // Rendering
 ///////////////////////////////////////////////////////////////////////////////
 
-void LayerRenderer::prepare(bool opaque) {
+void LayerRenderer::prepareDirty(float left, float top, float right, float bottom, bool opaque) {
     LAYER_RENDERER_LOGD("Rendering into layer, fbo = %d", mLayer->fbo);
 
 #if RENDER_LAYERS_AS_REGIONS
@@ -35,7 +35,7 @@
 
     glBindFramebuffer(GL_FRAMEBUFFER, mLayer->fbo);
 
-    OpenGLRenderer::prepare(opaque);
+    OpenGLRenderer::prepareDirty(0.0f, 0.0f, mLayer->width, mLayer->height, opaque);
 }
 
 void LayerRenderer::finish() {