Android: autogenerate Java GpuFeatures

No change to logic. This autogenerates GpuFeatures.java from the c++
feature definitions using java_cpp_features. This updates
ProductionSupportedFlagList to depend on the new constant.

This rewrites some feature definitions to conform to java_cpp_features's
supported syntaxes.

Fixed: 1132502
Test: autoninja -C out/Default system_webview_apk
Change-Id: I9a5b562e7b034d5ed8606bff8dd218ca2d5e0790
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2432195
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Auto-Submit: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813049}

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

@@ -7,6 +7,7 @@ package org.chromium.android_webview.common;
 import org.chromium.base.BaseSwitches;
 import org.chromium.cc.base.CcSwitches;
 import org.chromium.components.metrics.MetricsSwitches;
+import org.chromium.gpu.config.GpuFeatures;
 import org.chromium.gpu.config.GpuSwitches;
 
 /**
@@ -64,7 +65,8 @@ public final class ProductionSupportedFlagList {
             Flag.commandLine(GpuSwitches.IGNORE_GPU_BLOCKLIST,
                     "Overrides the built-in software rendering list and enables "
                             + "GPU acceleration on unsupported device configurations."),
-            Flag.baseFeature("EnableSharedImageForWebview", "Enables shared images for WebView."),
+            Flag.baseFeature(GpuFeatures.ENABLE_SHARED_IMAGE_FOR_WEBVIEW,
+                    "Enables shared images for WebView."),
             Flag.baseFeature("VizForWebView", "Enables Viz for WebView."),
             Flag.baseFeature(AwFeatures.WEBVIEW_CONNECTIONLESS_SAFE_BROWSING,
                     "Uses GooglePlayService's 'connectionless' APIs for Safe Browsing "

gpu/config/BUILD.gn

@@ -245,9 +245,19 @@ if (is_android) {
     template = "android/java/src/org/chromium/gpu/config/GpuSwitches.java.tmpl"
   }
 
+  java_cpp_features("java_features_srcjar") {
+    # External code should depend on ":config_java" instead.
+    visibility = [ ":*" ]
+    sources = [ "gpu_finch_features.cc" ]
+    template = "android/java/src/org/chromium/gpu/config/GpuFeatures.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" ]
+    # Right now, this only includes the Java switches/features. But if we need
+    # more Java files, they should be added here as necessary.
+    srcjar_deps = [
+      ":java_features_srcjar",
+      ":java_switches_srcjar",
+    ]
   }
 }

gpu/config/android/java/src/org/chromium/gpu/config/GpuFeatures.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;
+
+/**
+ * Constants for the names of GPU Features.
+ */
+public final class GpuFeatures {{
+
+{NATIVE_FEATURES}
+
+    // Prevent instantiation.
+    private GpuFeatures() {{}}
+}}

gpu/config/gpu_finch_features.cc

@@ -31,16 +31,17 @@ const base::Feature kAImageReader{"AImageReader",
 
 // Enable GPU Rasterization by default. This can still be overridden by
 // --force-gpu-rasterization or --disable-gpu-rasterization.
-#if defined(OS_MAC) || defined(OS_WIN) || defined(OS_CHROMEOS) || \
-    defined(OS_ANDROID) || defined(OS_FUCHSIA)
 // DefaultEnableGpuRasterization has launched on Mac, Windows, ChromeOS, and
 // Android.
 const base::Feature kDefaultEnableGpuRasterization{
-    "DefaultEnableGpuRasterization", base::FEATURE_ENABLED_BY_DEFAULT};
+  "DefaultEnableGpuRasterization",
+#if defined(OS_MAC) || defined(OS_WIN) || defined(OS_CHROMEOS) || \
+    defined(OS_ANDROID) || defined(OS_FUCHSIA)
+      base::FEATURE_ENABLED_BY_DEFAULT
 #else
-const base::Feature kDefaultEnableGpuRasterization{
-    "DefaultEnableGpuRasterization", base::FEATURE_DISABLED_BY_DEFAULT};
+      base::FEATURE_DISABLED_BY_DEFAULT
 #endif
+};
 
 // Enable out of process rasterization by default.  This can still be overridden
 // by --disable-oop-rasterization.
@@ -54,13 +55,14 @@ const base::Feature kGpuProcessHighPriorityWin{
 #endif
 
 // Use ThreadPriority::DISPLAY for GPU main, viz compositor and IO threads.
-#if defined(OS_ANDROID) || defined(OS_CHROMEOS) || defined(OS_WIN)
 const base::Feature kGpuUseDisplayThreadPriority{
-    "GpuUseDisplayThreadPriority", base::FEATURE_ENABLED_BY_DEFAULT};
+  "GpuUseDisplayThreadPriority",
+#if defined(OS_ANDROID) || defined(OS_CHROMEOS) || defined(OS_WIN)
+      base::FEATURE_ENABLED_BY_DEFAULT
 #else
-const base::Feature kGpuUseDisplayThreadPriority{
-    "GpuUseDisplayThreadPriority", base::FEATURE_DISABLED_BY_DEFAULT};
+      base::FEATURE_DISABLED_BY_DEFAULT
 #endif
+};
 
 // Gpu watchdog V2 to simplify the logic and reduce GPU hangs
 const base::Feature kGpuWatchdogV2{"GpuWatchdogV2",