Improve tracking of bound FBOs in GrGLGpu.

src/gpu/gl/debug/GrGLCreateDebugInterface.cpp

Index: src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
diff --git a/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp b/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
index 77a1422af173212a3bf7178295e2906929b5e875..b4643cc6d72f1acc165774cbe4f9e9e6bd579b16 100644
--- a/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
+++ b/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
@@ -382,7 +382,8 @@ GrGLvoid GR_GL_FUNCTION_TYPE debugGLReadPixels(GrGLint x,
                                                              GrGLenum renderbuffertarget,
                                                              GrGLuint renderBufferID) {
 
-     GrAlwaysAssert(GR_GL_FRAMEBUFFER == target);
+    GrAlwaysAssert(GR_GL_FRAMEBUFFER == target || GR_GL_READ_FRAMEBUFFER == target ||
+                   GR_GL_DRAW_FRAMEBUFFER == target);
      GrAlwaysAssert(GR_GL_COLOR_ATTACHMENT0 == attachment ||
                     GR_GL_DEPTH_ATTACHMENT == attachment ||
                     GR_GL_STENCIL_ATTACHMENT == attachment);
@@ -422,7 +423,8 @@ GrGLvoid GR_GL_FUNCTION_TYPE debugGLReadPixels(GrGLint x,
                                                           GrGLuint textureID,
                                                           GrGLint level) {
 
-     GrAlwaysAssert(GR_GL_FRAMEBUFFER == target);
+    GrAlwaysAssert(GR_GL_FRAMEBUFFER == target || GR_GL_READ_FRAMEBUFFER == target ||
+                   GR_GL_DRAW_FRAMEBUFFER == target);
      GrAlwaysAssert(GR_GL_COLOR_ATTACHMENT0 == attachment ||
                     GR_GL_DEPTH_ATTACHMENT == attachment ||
                     GR_GL_STENCIL_ATTACHMENT == attachment);