Android: expose gpu_switches to Java

No change to logic. This exposes gpu_switches to Java with
java_cpp_strings.

Fixed: 1112006
Test: autoninja -C out/Default system_webview_apk
Change-Id: I84fb22671a6ce42c288b2772f3d49722ccc79f99
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2343776
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797074}

android_webview/BUILD.gn

@@ -668,6 +668,7 @@ android_library("common_java") {
   deps = [
     "//base:base_java",
     "//components/metrics:metrics_java",
+    "//gpu/config:config_java",
     "//third_party/android_deps:androidx_annotation_annotation_java",
   ]
   srcjar_deps = [ ":common_java_switches_srcjar" ]

android_webview/java/src/org/chromium/android_webview/common/ProductionSupportedFlagList.java

@@ -6,6 +6,7 @@ package org.chromium.android_webview.common;
 
 import org.chromium.base.BaseSwitches;
 import org.chromium.components.metrics.MetricsSwitches;
+import org.chromium.gpu.config.GpuSwitches;
 
 /**
  * List of experimental features/flags supported for user devices. Add features/flags to this list
@@ -57,7 +58,7 @@ public final class ProductionSupportedFlagList {
             Flag.commandLine(BaseSwitches.ENABLE_CRASH_REPORTER_FOR_TESTING,
                     "Used for turning on Breakpad crash reporting in a debug environment where "
                             + "crash reporting is typically compiled but disabled."),
-            Flag.commandLine("disable-gpu-rasterization",
+            Flag.commandLine(GpuSwitches.DISABLE_GPU_RASTERIZATION,
                     "Disables GPU rasterization, i.e. rasterizes on the CPU only."),
             Flag.baseFeature("OutOfBlinkCors",
                     "Moves CORS logic into the Network Service (rather than inside the blink "

gpu/config/BUILD.gn

@@ -7,6 +7,10 @@ import("//build/config/chromecast_build.gni")
 import("//build/config/ui.gni")
 import("//gpu/vulkan/features.gni")
 
+if (is_android) {
+  import("//build/config/android/rules.gni")
+}
+
 group("config") {
   if (is_component_build) {
     public_deps = [ "//gpu" ]
@@ -225,3 +229,18 @@ source_set("config_sources") {
     ]
   }
 }
+
+if (is_android) {
+  java_cpp_strings("java_switches_srcjar") {
+    # External code should depend on ":config_java" instead.
+    visibility = [ ":*" ]
+    sources = [ "gpu_switches.cc" ]
+    template = "android/java/src/org/chromium/gpu/GpuSwitches.java.tmpl"
+  }
+
+  android_library("config_java") {
+    # Right now, this only includes the Java switches. But if we need more Java
+    # files, they should be added here as necessary.
+    srcjar_deps = [ ":java_switches_srcjar" ]
+  }
+}

gpu/config/android/java/src/org/chromium/gpu/GpuSwitches.java.tmpl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.gpu.config;
+
+/**
+ * Contains all of the command line switches that are specific to the gpu/ layer.
+ */
+public final class GpuSwitches {{
+
+{NATIVE_STRINGS}
+
+    // Prevent instantiation.
+    private GpuSwitches() {{}}
+}}