Revert of Rebaseline imagemagnifier and dropshadowimagefilter tests. (patchset #3 id:40001 of https://codereview.chromium.org/685523002/)

Reason for revert:
Getting to revert for failures on image filter tests in Skia and Blink

Original issue's description:
> Rebaseline imagemagnifier and dropshadowimagefilter tests.
>
> BUG=skia:
> TBR=hcm@google.com
> NOTRY=true
>
> Committed: https://skia.googlesource.com/skia/+/0fc71ea432d3895ede198a24080f877e607cd264

TBR=senorblanco@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/678043003
diff --git a/expectations/gm/Test-ChromeOS-Link-HD4000-x86_64-Debug/expected-results.json b/expectations/gm/Test-ChromeOS-Link-HD4000-x86_64-Debug/expected-results.json
index 901c4af..9b8a3cf 100644
--- a/expectations/gm/Test-ChromeOS-Link-HD4000-x86_64-Debug/expected-results.json
+++ b/expectations/gm/Test-ChromeOS-Link-HD4000-x86_64-Debug/expected-results.json
@@ -2798,19 +2798,17 @@
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          10690981673844438779
+          10074125510709354851
         ]
-      ], 
-      "reviewed-by-human": true
+      ]
     }, 
     "dropshadowimagefilter_8888.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          17741586089922604508
+          12348002540930970048
         ]
-      ], 
-      "reviewed-by-human": true
+      ]
     }, 
     "drrect_565.png": {
       "allowed-digests": [
@@ -4429,7 +4427,7 @@
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          16124800527256131619
+          7955099457759770546
         ]
       ], 
       "reviewed-by-human": true
@@ -4438,7 +4436,7 @@
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          1411254310484647352
+          6913141539607550299
         ]
       ], 
       "reviewed-by-human": true