Android: Make proguard_configs explicit inputs for "gn analyze"

gn analyze does not use depfile information, which causes it to not know
that builds need to happen when proguard flags change.

To work around this, this change marks the proguard_configs as inputs to
(somewhat arbitrary) java actions.

Bug: 827197
Change-Id: I1522daa0e3782ac1989cf4e234d8409663bf1357
Reviewed-on: https://chromium-review.googlesource.com/985900Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547799}

build/config/android/internal_rules.gni

@@ -1387,6 +1387,7 @@ if (enable_java_templates) {
     # possibly broken symlinks to them) get copied into the output
     # directory.
     copy_ex(_output_jar_target) {
+      forward_variables_from(invoker, [ "inputs" ])
       deps = _deps
       if (defined(invoker.deps)) {
         deps += invoker.deps
@@ -2496,6 +2497,7 @@ if (enable_java_templates) {
              "main_class cannot be used for target of type ${invoker.type}")
     }
 
+    # The only target that might have no prebuilt and no sources is a java_binary.
     if (_is_prebuilt || _has_sources) {
       if (defined(invoker.output_name)) {
         _output_name = invoker.output_name
@@ -2771,6 +2773,14 @@ if (enable_java_templates) {
         }
         output_jar_path = _final_jar_path
         deps = _accumulated_deps
+
+        # Although these will be listed as deps in the depfile, they must also
+        # appear here so that "gn analyze" knows about them.
+        # https://crbug.com/827197
+        if (defined(invoker.proguard_configs)) {
+          inputs = invoker.proguard_configs
+          deps += _srcjar_deps  # For the aapt-generated proguard rules.
+        }
       }
       _accumulated_deps += [ ":$_process_prebuilt_target_name" ]
 

build/config/android/rules.gni

@@ -1414,6 +1414,13 @@ if (enable_java_templates) {
           _build_config,
         ]
 
+        # Although these will be listed as deps in the depfile, they must also
+        # appear here so that "gn analyze" knows about them.
+        # https://crbug.com/827197
+        if (defined(invoker.proguard_configs)) {
+          inputs += invoker.proguard_configs
+        }
+
         output_jar_path = invoker.output
         args = [
           "--proguard-configs=@FileArg($_rebased_build_config:deps_info:proguard_all_configs)",
@@ -1543,6 +1550,13 @@ if (enable_java_templates) {
         _build_config,
       ]
 
+      # Although these will be listed as deps in the depfile, they must also
+      # appear here so that "gn analyze" knows about them.
+      # https://crbug.com/827197
+      if (defined(invoker.proguard_configs)) {
+        inputs += invoker.proguard_configs
+      }
+
       outputs = [
         invoker.output,
       ]
@@ -3254,6 +3268,9 @@ if (enable_java_templates) {
                                "testonly",
                                "visibility",
                              ])
+      public_deps = [
+        ":$_unpack_target_name",
+      ]
       deps = []
       if (defined(_jar_target_name)) {
         deps += [ ":$_jar_target_name" ]