Bump picture version for uniqueID-less SkImageFilter.

Remove writing of the uniqueID, and put reading behind a version check.

BUG=skia:3559

Review URL: https://codereview.chromium.org/1010433003
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 0cb954c..f1553e2 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -100,9 +100,10 @@
 
     uint32_t flags = buffer.readUInt();
     fCropRect = CropRect(rect, flags);
-    // FIXME: this is now unused; and should be made conditional on the next SkPicture version bump.
-    // See skbug.com/3559.
-    (void) buffer.readUInt();
+    if (buffer.isVersionLT(SkReadBuffer::kImageFilterNoUniqueID_Version)) {
+
+        (void) buffer.readUInt();
+    }
     return buffer.isValid();
 }
 
@@ -161,9 +162,6 @@
     }
     buffer.writeRect(fCropRect.rect());
     buffer.writeUInt(fCropRect.flags());
-    // FIXME: this is now unused; and should be removed on the next SkPicture version bump.
-    // See skbug.com/3559.
-    buffer.writeUInt(0);
 }
 
 bool SkImageFilter::filterImage(Proxy* proxy, const SkBitmap& src,
diff --git a/src/core/SkReadBuffer.h b/src/core/SkReadBuffer.h
index a24ca55..65255e6 100644
--- a/src/core/SkReadBuffer.h
+++ b/src/core/SkReadBuffer.h
@@ -55,6 +55,7 @@
         kDropShadowMode_Version            = 37,
         kPictureImageFilterResolution_Version = 38,
         kPictureImageFilterLevel_Version   = 39,
+        kImageFilterNoUniqueID_Version     = 40,
     };
 
     /**