Bug 1230550 - Enable the real APZ on b2gdroid in a safer way. r=fabrice

mobile/android/b2gdroid/app/b2gdroid.js

@@ -543,7 +543,6 @@ pref("layers.acceleration.disabled", false);
 pref("layers.offmainthreadcomposition.enabled", true);
 pref("layers.async-video.enabled", true);
 
-#ifdef MOZ_ANDROID_APZ
 pref("layers.async-pan-zoom.enabled", true);
 // APZ physics settings, tuned by UX designers
 pref("apz.axis_lock.mode", 2); // Use "sticky" axis locking
@@ -554,7 +553,6 @@ pref("apz.fling_curve_function_y2", "1.0");
 pref("apz.fling_curve_threshold_inches_per_ms", "0.01");
 pref("apz.fling_friction", "0.0019");
 pref("apz.max_velocity_inches_per_ms", "0.07");
-#endif
 
 pref("layers.progressive-paint", true);
 pref("layers.low-precision-buffer", true);

mobile/android/b2gdroid/config/mozconfigs/common

@@ -43,8 +43,6 @@ ac_add_options --with-android-version=9
 ac_add_options --with-system-zlib
 ac_add_options --enable-update-channel=${MOZ_UPDATE_CHANNEL}
 
-ac_add_options --enable-android-apz
-
 # Treat warnings as errors in directories with FAIL_ON_WARNINGS.
 ac_add_options --enable-warnings-as-errors
 

mobile/android/b2gdroid/confvars.sh

@@ -48,6 +48,7 @@ MOZ_PLACES=
 MOZ_SOCIAL=
 MOZ_ANDROID_HISTORY=1
 MOZ_DISABLE_EXPORT_JS=1
+MOZ_ANDROID_APZ=1
 
 # use custom widget for html:select
 MOZ_USE_NATIVE_POPUP_WINDOWS=1