cc: Allow output readback/copy requests to specify a sub-rect to copy.

cc/test/solid_color_content_layer_client.cc

Index: cc/test/solid_color_content_layer_client.cc
diff --git a/cc/test/solid_color_content_layer_client.cc b/cc/test/solid_color_content_layer_client.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2d84947b7071cea5f47155565e0f738d156c3de7
--- /dev/null
+++ b/cc/test/solid_color_content_layer_client.cc
@@ -0,0 +1,29 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/test/solid_color_content_layer_client.h"
+
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkPaint.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/rect_f.h"
+
+namespace cc {
+
+void SolidColorContentLayerClient::PaintContents(
+    SkCanvas* canvas, gfx::Rect rect, gfx::RectF* opaque_rect) {
+  SkPaint paint;
+  paint.setStyle(SkPaint::kFill_Style);
+  paint.setColor(color_);
+
+  canvas->clear(SK_ColorTRANSPARENT);
+  canvas->drawRect(
+      SkRect::MakeXYWH(rect.x(), rect.y(), rect.width(), rect.height()),
+      paint);
+
+  if (SkColorGetA(color_) == 255)
+    *opaque_rect = rect;
+}
+
+}  // namespace cc