AW: paler yellow for highlight-all-webviews

No change to logic. This swaps out the color of highlight-all-webviews
for a paler shade of yellow, and makes it more transparent. This is
based on feedback from the test team.

Fixed: 1066983
Test: Manual - load http://www.cnn.com/ and compare color filters
Change-Id: I27b22cae1f233ea9f4d410d091520c25d74309d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2132929
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Bo <boliu@chromium.org>
Auto-Submit: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755515}

android_webview/java/src/org/chromium/android_webview/AwContents.java

@@ -3656,7 +3656,7 @@ public class AwContents implements SmartClipProvider {
 
             // Tint everything one color, to make WebViews easier to spot.
             if (CommandLine.getInstance().hasSwitch(AwSwitches.HIGHLIGHT_ALL_WEBVIEWS)) {
-                int semiTransparentYellow = Color.argb(127, 255, 255, 0);
+                int semiTransparentYellow = Color.argb(80, 252, 252, 109);
                 canvas.drawColor(semiTransparentYellow);
             }
         }