Remove redundant FBO query methods.

Several query methods simply wrapped a NULL check with a default
return value. Most of these safety checks were unnecessary.

BUG=angle:660

Change-Id: I0ac6897f06be082c8efab8721920d1b51ba999ee
Reviewed-on: https://chromium-review.googlesource.com/205606
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libGLESv2/Context.cpp b/src/libGLESv2/Context.cpp
index ac09e0e..fe7b361 100644
--- a/src/libGLESv2/Context.cpp
+++ b/src/libGLESv2/Context.cpp
@@ -2594,7 +2594,7 @@
 
     if (mask & GL_DEPTH_BUFFER_BIT)
     {
-        if (mState.depthStencil.depthMask && framebufferObject->getDepthbufferType() != GL_NONE)
+        if (mState.depthStencil.depthMask && framebufferObject->getDepthbuffer() != NULL)
         {
             clearParams.clearDepth = true;
         }
@@ -2602,7 +2602,7 @@
 
     if (mask & GL_STENCIL_BUFFER_BIT)
     {
-        if (framebufferObject->getStencilbufferType() != GL_NONE)
+        if (framebufferObject->getStencilbuffer() != NULL)
         {
             rx::RenderTarget *depthStencil = framebufferObject->getStencilbuffer()->getDepthStencil();
             if (!depthStencil)