CCA: Negative value in calc with calc(-1 * ...)

Replace all calc(0px - ...) with calc(-1 * ...) for avoiding 'Use "0"
for zero-width lengths (i.e. 0px -> 0)' presubmit warning.

Bug: b/172340545
Test: Manually check all layout looks the same.
Change-Id: I7a5b80da98f9248ebb929eb576bae9845e781442
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2602055
Commit-Queue: Inker Kuo <inker@chromium.org>
Commit-Queue: Shik Chen <shik@chromium.org>
Auto-Submit: Inker Kuo <inker@chromium.org>
Reviewed-by: Shik Chen <shik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839308}

chromeos/components/camera_app_ui/resources/css/main.css

@@ -73,12 +73,12 @@ body.tab-navigation input:focus::after {
 
   border: 2px solid var(--focus-color);
   border-radius: 4px;
-  bottom: calc(0px - var(--focus-ring-size));
+  bottom: calc(-1 * var(--focus-ring-size));
   content: '';
-  left: calc(0px - var(--focus-ring-size));
+  left: calc(-1 * var(--focus-ring-size));
   position: absolute;
-  right: calc(0px - var(--focus-ring-size));
-  top: calc(0px - var(--focus-ring-size));
+  right: calc(-1 * var(--focus-ring-size));
+  top: calc(-1 * var(--focus-ring-size));
 }
 
 .cancel-animate {
@@ -367,7 +367,7 @@ body.tab-navigation .mode-item>input:focus::after {
 }
 
 body.tab-navigation .mode-item>input:focus + span::after {
-  --negative-size: calc(0px - var(--focus-ring-gap));
+  --negative-size: calc(-1 * var(--focus-ring-gap));
 
   border: var(--focus-ring-border) solid var(--focus-color);
   border-radius: 23px/50%;