Revert of Improve tracking of bound FBOs in GrGLGpu.

src/gpu/gl/GrGLGpu.h

Index: src/gpu/gl/GrGLGpu.h
diff --git a/src/gpu/gl/GrGLGpu.h b/src/gpu/gl/GrGLGpu.h
index 807ed8788e00414a4fd016c3a03ed18c9c465c4c..b93080b70037d2b5a624b0b9996dc7b798adad12 100644
--- a/src/gpu/gl/GrGLGpu.h
+++ b/src/gpu/gl/GrGLGpu.h
@@ -246,28 +246,9 @@
     // ensures that such operations don't negatively interact with tracking bound textures.
     void setScratchTextureUnit();
 
-    // Binds the render target, sets the viewport, tracks dirty are for resolve, and tracks whether
-    // mip maps need rebuilding. bounds is region that may be modified by the draw. NULL means whole
-    // target. Can be an empty rect.
-    void prepareToDrawToRenderTarget(GrGLRenderTarget*, const SkIRect* bounds);
-
-    // On older GLs there may not be separate FBO bindings for draw and read. In that case these
-    // alias each other.
-    enum FBOBinding {
-        kDraw_FBOBinding, // drawing or dst of blit
-        kRead_FBOBinding, // src of blit, read pixels.
-
-        kLast_FBOBinding = kRead_FBOBinding
-    };
-    static const int kFBOBindingCnt = kLast_FBOBinding + 1;
-
-    // binds the FBO and returns the GL enum of the framebuffer target it was bound to.
-    GrGLenum bindFBO(FBOBinding, const GrGLFBO*);
-    // This version invokes a workaround for a bug in Chromium. It should be called before
-    // attachments are changed on a FBO.
-    GrGLenum bindFBOForAddingAttachments(const GrGLFBO*);
-
-    void setViewport(const GrGLIRect& viewport);
+    // bounds is region that may be modified and therefore has to be resolved.
+    // NULL means whole target. Can be an empty rect.
+    void flushRenderTarget(GrGLRenderTarget*, const SkIRect* bounds);
 
     void flushStencil(const GrStencilSettings&);
     void flushHWAAState(GrRenderTarget* rt, bool useHWAA, bool isLineDraw);
@@ -300,14 +281,15 @@
     bool createRenderTargetObjects(const GrSurfaceDesc&, bool budgeted, GrGLuint texID, 
                                    GrGLRenderTarget::IDDesc*);
 
-    static const FBOBinding kInvalidFBOBinding = static_cast<FBOBinding>(-1);
-
-    // Binds a surface as an FBO. A temporary FBO ID may be used if the surface is not already
-    // a render target. Afterwards unbindSurfaceAsFBOForCopy must be called with the value returned.
-    FBOBinding bindSurfaceAsFBOForCopy(GrSurface*, FBOBinding, GrGLIRect* viewport);
-
-    // Must be matched with bindSurfaceAsFBOForCopy.
-    void unbindSurfaceAsFBOForCopy(FBOBinding);
+    enum TempFBOTarget {
+        kSrc_TempFBOTarget,
+        kDst_TempFBOTarget
+    };
+
+    GrGLuint bindSurfaceAsFBO(GrSurface* surface, GrGLenum fboTarget, GrGLIRect* viewport,
+                              TempFBOTarget tempFBOTarget);
+
+    void unbindTextureFromFBO(GrGLenum fboTarget);
 
     GrGLContext fGLContext;
 
@@ -327,9 +309,10 @@
         kUnknown_TriState
     };
 
-    SkAutoTUnref<GrGLFBO> fTempSrcFBO;
-    SkAutoTUnref<GrGLFBO> fTempDstFBO;
-    SkAutoTUnref<GrGLFBO> fStencilClearFBO;
+    GrGLuint                    fTempSrcFBOID;
+    GrGLuint                    fTempDstFBOID;
+
+    GrGLuint                    fStencilClearFBOID;
 
     // last scissor / viewport scissor state seen by the GL.
     struct {
@@ -475,13 +458,8 @@
     GrPipelineBuilder::DrawFace fHWDrawFace;
     TriState                    fHWWriteToColor;
     TriState                    fHWDitherEnabled;
+    uint32_t                    fHWBoundRenderTargetUniqueID;
     SkTArray<uint32_t, true>    fHWBoundTextureUniqueIDs;
-
-    // Track fbo binding state.
-    struct HWFBOBinding {
-        SkAutoTUnref<const GrGLFBO> fFBO;
-        void invalidate() { fFBO.reset(NULL); }
-    } fHWFBOBinding[kFBOBindingCnt];
 
     ///@}