Revert "Remove ".dd" extension from VR icons"

This reverts commit c00fe466.

Reason for revert: Breaks canary push

Original change's description:
> Remove ".dd" extension from VR icons
> 
> Bug: 834499
> Change-Id: I673de864b05a6e6e30a848631d15dce3743ca946
> Reviewed-on: https://chromium-review.googlesource.com/1023049
> Reviewed-by: Richard Coles <torne@chromium.org>
> Reviewed-by: agrieve <agrieve@chromium.org>
> Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#552773}

TBR=mthiesse@chromium.org,torne@chromium.org,agrieve@chromium.org

NOTRY=true

Bug: 834499
Change-Id: I5b0094ad101b5f734c58156e86a453c8566a918c
Reviewed-on: https://chromium-review.googlesource.com/1028092Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553577}

build/android/gyp/compile_resources.py

@@ -55,8 +55,8 @@ _PNG_WEBP_BLACKLIST_PATTERN = re.compile('|'.join([
     r'.*star_gray\.png',
     # Android requires pngs for 9-patch images.
     r'.*\.9\.png',
-    # Daydream requires pngs for icon files.
-    r'daydream_icon_.*\.png']))
+    # Daydream (*.dd) requires pngs for icon files.
+    r'.*\.dd\.png']))
 
 # Regular expression for package declaration in 'aapt dump resources' output.
 _RE_PACKAGE_DECLARATION = re.compile(