Don't flush on read/write pixels unless necessary

src/gpu/GrSurface.cpp

Index: src/gpu/GrSurface.cpp
diff --git a/src/gpu/GrSurface.cpp b/src/gpu/GrSurface.cpp
index 52ab4fd11dc2963fa3612b482d84ea8f33eafea7..d15cbdf6e26ccc7fd3b3745cb9ced18747132395 100644
--- a/src/gpu/GrSurface.cpp
+++ b/src/gpu/GrSurface.cpp
@@ -44,3 +44,39 @@ bool GrSurface::savePixels(const char* filename) {
 
     return true;
 }
+
+bool GrSurface::hasPendingRead() const {
+    const GrTexture* thisTex = this->asTexture();
+    if (thisTex && thisTex->internalHasPendingRead()) {
+        return true;
+    }
+    const GrRenderTarget* thisRT = this->asRenderTarget();
+    if (thisRT && thisRT->internalHasPendingRead()) {
+        return true;
+    }
+    return false;
+}
+
+bool GrSurface::hasPendingWrite() const {
+    const GrTexture* thisTex = this->asTexture();
+    if (thisTex && thisTex->internalHasPendingWrite()) {
+        return true;
+    }
+    const GrRenderTarget* thisRT = this->asRenderTarget();
+    if (thisRT && thisRT->internalHasPendingWrite()) {
+        return true;
+    }
+    return false;
+}
+
+bool GrSurface::hasPendingIO() const {
+    const GrTexture* thisTex = this->asTexture();
+    if (thisTex && thisTex->internalHasPendingIO()) {
+        return true;
+    }
+    const GrRenderTarget* thisRT = this->asRenderTarget();
+    if (thisRT && thisRT->internalHasPendingIO()) {
+        return true;
+    }
+    return false;
+}