[blimp] Change to use SHA-256 instead of SHA-1 for unique ids

blimp/engine/renderer/engine_image_serialization_processor.cc

Index: blimp/engine/renderer/engine_image_serialization_processor.cc
diff --git a/blimp/engine/renderer/engine_image_serialization_processor.cc b/blimp/engine/renderer/engine_image_serialization_processor.cc
index d59e07e7d03699e5db44ed266adc03132e771692..0f3f27e4ca74fd411cecc902e8adee380e483ff7 100644
--- a/blimp/engine/renderer/engine_image_serialization_processor.cc
+++ b/blimp/engine/renderer/engine_image_serialization_processor.cc
@@ -11,9 +11,7 @@
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
-#include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
 #include "base/trace_event/trace_event.h"
 #include "blimp/common/blob_cache/id_util.h"
 #include "blimp/common/compositor/webp_decoder.h"
@@ -76,7 +74,7 @@ class WebPImageEncoder : public SkPixelSerializer {
     picture.height = pixmap.height();
 
     const BlobId blob_id = CalculateBlobId(pixmap.addr(), pixmap.getSafeSize());
-    std::string blob_id_hex = FormatBlobId(blob_id);
+    std::string blob_id_hex = BlobIdToString(blob_id);
 
     // Create proto with all requires information.
     BlobCacheImageMetadata proto;