Reimplement deserialization of SkImageFilter's uniqueID.

9fa60d ("Simplify flattening to just write enough ... ") simplified just
a tad too much. In particular, it disabled deserialization of
SkImageFilter's uniqueID, which in turn caused the failure of
SkImageFilter's cache, which caused a large regression in Chrome's SVG
filter performance.

The medium-term fix is to switch to the new SkRecordDraw SkPicture
backend, which will make the unique IDs unnecessary.

This change is an "in case of emergecy" CL, in the event that there are
problems switching on the new backend in Chrome. For that reason, it's
minimalist: only the filters used by Chrome are modified, and whitespace
changes are kept to a minimum. In this way, it should be easy to revert
once the new backend goes in.

R=reed@google.com

Author: senorblanco@chromium.org

Review URL: https://codereview.chromium.org/503833002

1 files changed, 8 insertions, 5 deletions

diff --git a/include/effects/SkMergeImageFilter.h b/include/effects/SkMergeImageFilter.h
index a9a14a95cd..5e723aa290 100644
--- a/include/effects/SkMergeImageFilter.h
+++ b/include/effects/SkMergeImageFilter.h
@@ -18,15 +18,17 @@ public:
 
     static SkMergeImageFilter* Create(SkImageFilter* first, SkImageFilter* second,
                                       SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode,
-                                      const CropRect* cropRect = NULL) {
+                                      const CropRect* cropRect = NULL,
+                                      uint32_t uniqueID = 0) {
         SkImageFilter* inputs[2] = { first, second };
         SkXfermode::Mode modes[2] = { mode, mode };
-        return SkNEW_ARGS(SkMergeImageFilter, (inputs, 2, modes, cropRect));
+        return SkNEW_ARGS(SkMergeImageFilter, (inputs, 2, modes, cropRect, uniqueID));
     }
     static SkMergeImageFilter* Create(SkImageFilter* filters[], int count,
                                       const SkXfermode::Mode modes[] = NULL,
-                                      const CropRect* cropRect = NULL) {
-        return SkNEW_ARGS(SkMergeImageFilter, (filters, count, modes, cropRect));
+                                      const CropRect* cropRect = NULL,
+                                      uint32_t uniqueID = 0) {
+        return SkNEW_ARGS(SkMergeImageFilter, (filters, count, modes, cropRect, uniqueID));
     }
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMergeImageFilter)
@@ -34,7 +36,8 @@ public:
 protected:
     SkMergeImageFilter(SkImageFilter* filters[], int count,
                        const SkXfermode::Mode modes[],
-                       const CropRect* cropRect);
+                       const CropRect* cropRect,
+                       uint32_t uniqueID);
 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
     explicit SkMergeImageFilter(SkReadBuffer& buffer);
 #endif