GN: Add missing deps for incremental apks.

build/config/android/rules.gni

Index: build/config/android/rules.gni
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 2c8c4d66b57f84966f5706bb1de77173fc59301b..e33b7a8d12b072fee212a7fd78b0b7c236430e35 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1451,7 +1451,8 @@ template("android_apk") {
   }
 
   if (_native_libs != []) {
-    action("${_template_name}__prepare_native") {
+    _prepare_native_target_name = "${_template_name}__prepare_native"
+    action(_prepare_native_target_name) {
       forward_variables_from(invoker,
                              [
                                "data_deps",
@@ -1539,7 +1540,10 @@ template("android_apk") {
              ":$process_resources_target",
              ":$final_dex_target_name",
            ]
-    incremental_deps = _android_manifest_deps + [ ":$process_resources_target" ]
+    incremental_deps = _android_manifest_deps + [
+                         ":$java_target",

[pkotwicz, 2015/09/24 21:31:53]

I wonder whether we should add $java_target to deps in addition to
incremental_deps

What steps did you do to get a build failure? (I want to reproduce it to better
understand the issue). I understand that "final_dex_target_name" depends on
"java_target". However, I do not yet understand why the "java_target" dependency
is important here

[agrieve, 2015/09/24 22:22:57]

We shouldn't add it to deps, because it's not a direct dependency of the actual
apk. The actual APK needs only the classes.dex file, which includes $java_target
in it.

The template actually also doesn't need $java_target. I should have added it to
_incremental_final_deps, which I've now done.

To test it out, build any APK and add _incremental. 
e.g. ninja chrome_public_apk_incremental
Then run:
out-gn/Debug/bin/install_incremental_chrome_public_apk

+                         ":$process_resources_target",
+                       ]
     if (defined(invoker.deps)) {
       deps += invoker.deps
       incremental_deps += invoker.deps
@@ -1558,7 +1562,8 @@ template("android_apk") {
 
     if (_native_libs != [] && !_create_abi_split) {
       native_libs_dir = _native_libs_dir
-      deps += [ ":${_template_name}__prepare_native" ]
+      deps += [ ":$_prepare_native_target_name" ]
+      incremental_deps += [ ":$_prepare_native_target_name" ]
     }
   }
 
@@ -1594,7 +1599,7 @@ template("android_apk") {
 
       native_libs_dir = _native_libs_dir
       deps = [
-        ":${_template_name}__prepare_native",
+        ":${_prepare_native_target_name}",
         ":${_manifest_rule}",
       ]
       incremental_deps = deps