AW: do not allow proguard to optimize ApiHelper classes

We recently introduced a series of ApiHelperFor* classes to help us
ensure the WebView APK's classes pass compile-time verification in order
to avoid runtime verification (which causes logspam and startup
penalties). However, proguard was inlining these classes in our release
builds, which re-introduced the class verification issues.

This adds an annotation to prevent inlining. The @DoNotInline
annotation is used to configure Proguard.

R=torne@chromium.org

      (tested on L,M,NMR1 with standalone webview and monochrome)
      android-webview-google -v --pageset-repeat=1
      (no startup penalty on L device)
      "StatusRetryVerificationAtRuntime" (ensure the fixed classes no
      longer show up)

Bug: 791099
Bug: 838702
Test: adb logcat | grep 'Failed resolution of'
Test: tools/perf/run_benchmark system_health.webview_startup --browser \
Test: use oatdump after installing APK. Then, grep for
Change-Id: I7e85718916313f03287e5f2d5fe8f51a02661f11
Reviewed-on: https://chromium-review.googlesource.com/1109464Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569848}

android_webview/glue/java/src/com/android/webview/chromium/ApiHelperForM.java

@@ -14,6 +14,7 @@ import android.webkit.WebViewClient;
 
 import org.chromium.android_webview.AwContentsClient;
 import org.chromium.android_webview.AwWebResourceResponse;
+import org.chromium.base.annotations.DoNotInline;
 
 /**
  * Utility class to use new APIs that were added in M (API level 23). These need to exist in a
@@ -21,6 +22,7 @@ import org.chromium.android_webview.AwWebResourceResponse;
  * encountering the new APIs.
  */
 
+@DoNotInline
 @TargetApi(Build.VERSION_CODES.M)
 public final class ApiHelperForM {
     private ApiHelperForM() {}

android_webview/glue/java/src/com/android/webview/chromium/ApiHelperForN.java

@@ -13,12 +13,14 @@ import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
 import org.chromium.android_webview.AwContentsClient;
+import org.chromium.base.annotations.DoNotInline;
 
 /**
  * Utility class to use new APIs that were added in N (API level 24). These need to exist in a
  * separate class so that Android framework can successfully verify WebView classes without
  * encountering the new APIs.
  */
+@DoNotInline
 @TargetApi(Build.VERSION_CODES.N)
 public final class ApiHelperForN {
     private ApiHelperForN() {}

android_webview/glue/java/src/com/android/webview/chromium/ApiHelperForO.java

@@ -11,12 +11,14 @@ import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
 import org.chromium.android_webview.AwRenderProcessGoneDetail;
+import org.chromium.base.annotations.DoNotInline;
 
 /**
  * Utility class to use new APIs that were added in O (API level 26). These need to exist in a
  * separate class so that Android framework can successfully verify WebView classes without
  * encountering the new APIs.
  */
+@DoNotInline
 @TargetApi(Build.VERSION_CODES.O)
 public final class ApiHelperForO {
     private ApiHelperForO() {}

android_webview/glue/java/src/com/android/webview/chromium/ApiHelperForOMR1.java

@@ -12,12 +12,14 @@ import android.webkit.WebViewClient;
 import org.chromium.android_webview.AwContentsClient;
 import org.chromium.android_webview.AwSafeBrowsingResponse;
 import org.chromium.base.Callback;
+import org.chromium.base.annotations.DoNotInline;
 
 /**
  * Utility class to use new APIs that were added in OMR1 (API level 27). These need to exist in a
  * separate class so that Android framework can successfully verify WebView classes without
  * encountering the new APIs.
  */
+@DoNotInline
 @TargetApi(Build.VERSION_CODES.O_MR1)
 public final class ApiHelperForOMR1 {
     private ApiHelperForOMR1() {}

base/BUILD.gn

@@ -2848,6 +2848,7 @@ if (is_android) {
       "android/java/src/org/chromium/base/annotations/AccessedByNative.java",
       "android/java/src/org/chromium/base/annotations/CalledByNative.java",
       "android/java/src/org/chromium/base/annotations/CalledByNativeUnchecked.java",
+      "android/java/src/org/chromium/base/annotations/DoNotInline.java",
       "android/java/src/org/chromium/base/annotations/JNIAdditionalImport.java",
       "android/java/src/org/chromium/base/annotations/JNINamespace.java",
       "android/java/src/org/chromium/base/annotations/MainDex.java",

base/android/java/src/org/chromium/base/annotations/DoNotInline.java

+// Copyright 2018 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.base.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * The annotated method or class should never be inlined.
+ *
+ * The annotated method (or methods on the annotated class) are guaranteed not to be inlined by
+ * Proguard. Other optimizations may still apply.
+ */
+@Target({ElementType.CONSTRUCTOR, ElementType.METHOD, ElementType.TYPE})
+@Retention(RetentionPolicy.CLASS)
+public @interface DoNotInline {}

base/android/proguard/chromium_code.flags

@@ -15,6 +15,7 @@
 -keep @interface org.chromium.base.annotations.AccessedByNative
 -keep @interface org.chromium.base.annotations.CalledByNative
 -keep @interface org.chromium.base.annotations.CalledByNativeUnchecked
+-keep @interface org.chromium.base.annotations.DoNotInline
 -keep @interface org.chromium.base.annotations.RemovableInRelease
 -keep @interface org.chromium.base.annotations.UsedByReflection
 
@@ -46,6 +47,15 @@
   @org.chromium.base.annotations.RemovableInRelease <methods>;
 }
 
+# Never inline classes or methods with this annotation, but allow shrinking and
+# obfuscation.
+-keepnames,allowobfuscation @org.chromium.base.annotations.DoNotInline class * {
+  *;
+}
+-keepclassmembernames,allowobfuscation class * {
+  @org.chromium.base.annotations.DoNotInline <methods>;
+}
+
 # Keep all CREATOR fields within Parcelable that are kept.
 -keepclassmembers class org.chromium.** implements android.os.Parcelable {
   public static *** CREATOR;

content/public/android/java/src/org/chromium/content/browser/ApiHelperForM.java

@@ -9,6 +9,7 @@ import android.os.Build;
 import android.view.ActionMode;
 import android.view.View;
 
+import org.chromium.base.annotations.DoNotInline;
 import org.chromium.content.browser.selection.FloatingActionModeCallback;
 import org.chromium.content.browser.selection.SelectionPopupControllerImpl;
 
@@ -18,6 +19,7 @@ import org.chromium.content.browser.selection.SelectionPopupControllerImpl;
  * encountering the new APIs.
  */
 
+@DoNotInline
 @TargetApi(Build.VERSION_CODES.M)
 public final class ApiHelperForM {
     private ApiHelperForM() {}