Move ReadPixels to the Framebuffer object and Impl.

BUG=angle:841

Change-Id: I71deac9e755b5dfa010596cd1f8a213c24d895bf
Reviewed-on: https://chromium-review.googlesource.com/232691
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/State.cpp b/src/libANGLE/State.cpp
index cbe5576..bd031b2 100644
--- a/src/libANGLE/State.cpp
+++ b/src/libANGLE/State.cpp
@@ -1247,6 +1247,8 @@
       case GL_STENCIL_WRITEMASK:                        *params = clampToInt(mDepthStencil.stencilWritemask);     break;
       case GL_STENCIL_BACK_WRITEMASK:                   *params = clampToInt(mDepthStencil.stencilBackWritemask); break;
       case GL_STENCIL_CLEAR_VALUE:                      *params = mStencilClearValue;                             break;
+      case GL_IMPLEMENTATION_COLOR_READ_TYPE:           *params = mReadFramebuffer->getImplementationColorReadType();   break;
+      case GL_IMPLEMENTATION_COLOR_READ_FORMAT:         *params = mReadFramebuffer->getImplementationColorReadFormat(); break;
       case GL_SAMPLE_BUFFERS:
       case GL_SAMPLES:
         {