Remove duplicate source file entry in chrome_browser.gypi
Resolve a ninja warning when building android:
ninja: warning: multiple rules generate obj/chrome/browser/ssl/browser.connection_security_helper_android.o. builds involving this target will not be correct; continuing anyway
The error originated from the first CL, revert and un-revert below:
https://codereview.chromium.org/
1123943002
https://codereview.chromium.org/
1135373003
https://codereview.chromium.org/
1124383007
BUG=NONE
TEST=Android build works; no ninja warning.
R=estark@chromium.org
Review URL: https://codereview.chromium.org/
1162743003
Cr-Commit-Position: refs/heads/master@{#332996}