Fix javac --incremental by using jmake for dependency analysis

build/config/android/config.gni

Index: build/config/android/config.gni
diff --git a/build/config/android/config.gni b/build/config/android/config.gni
index 7abf51ab9f49490ff18eb207bcdf3ef6e6653d9c..7ca1b70bac698973dc23d5050e9bbcc31229a23e 100644
--- a/build/config/android/config.gni
+++ b/build/config/android/config.gni
@@ -71,10 +71,16 @@ if (is_android) {
     disable_incremental_isolated_processes = false
 
     # Speed up incremental compiles by compiling only changed files.
-    incremental_javac = false
+    enable_incremental_javac = false
 
     # Speed up dexing using dx --incremental.
-    incremental_dx = true
+    enable_incremental_dx = is_debug
+
+    # Neither of these should ever be used for release builds since they are
+    # somewhat experimental and dx --incremental is known to not produce
+    # byte-for-byte identical output.
+    assert(!(enable_incremental_dx && !is_debug))
+    assert(!(enable_incremental_javac && !is_debug))
 
     # Adds intrumentation to each function. Writes a file with the order that
     # functions are called at startup.