libgui: update description of sourceCrop for captureScreen

Bug: 117892959
Test: builds
Change-Id: I757385465c537e51ddfc2fd830e1e2a35eab5883
diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index 3dffa8f..8f54fee 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -194,8 +194,7 @@
      * of the buffer. The caller should pick the data space and pixel format
      * that it can consume.
      *
-     * At the moment, sourceCrop is ignored and is always set to the visible
-     * region (projected display viewport) of the screen.
+     * sourceCrop is the crop on the logical display.
      *
      * reqWidth and reqHeight specifies the size of the buffer.  When either
      * of them is 0, they are set to the size of the logical display viewport.