Revert "remove legacy support for old old picture versions"

This reverts commit f3504d430cec35330017aa2af3a51083801c7dd9.

Reason for revert: breaks unittest in Printing unittest in chrome

Original change's description:
> remove legacy support for old old picture versions
> 
> Bug: skia:
> Change-Id: Ieb97eabdb18e8c7bfa86e6a1fc6e0389cd096daa
> Reviewed-on: https://skia-review.googlesource.com/89860
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=mtklein@google.com,fmalita@chromium.org,reed@google.com

Change-Id: I9f90da5dcfb9543f2f575fa7dc3b9c82996b041d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/90020
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/shaders/SkComposeShader.cpp b/src/shaders/SkComposeShader.cpp
index 2feae7788e..34e54863b7 100644
--- a/src/shaders/SkComposeShader.cpp
+++ b/src/shaders/SkComposeShader.cpp
@@ -43,12 +43,17 @@ sk_sp<SkFlattenable> SkComposeShader::CreateProc(SkReadBuffer& buffer) {
     sk_sp<SkShader> dst(buffer.readShader());
     sk_sp<SkShader> src(buffer.readShader());
     unsigned        mode = buffer.read32();
-    float           lerp = buffer.readScalar();
+
+    float lerp = 1;
+    if (!buffer.isVersionLT(SkReadBuffer::kComposeShaderCanLerp_Version)) {
+        lerp = buffer.readScalar();
+    }
 
     // check for valid mode before we cast to the enum type
-    if (!buffer.validate(mode <= (unsigned)SkBlendMode::kLastMode)) {
+    if (mode > (unsigned)SkBlendMode::kLastMode) {
         return nullptr;
     }
+
     return MakeCompose(std::move(dst), std::move(src), static_cast<SkBlendMode>(mode), lerp);
 }