Update WebView proguard configuration.

android_webview/apk/java/proguard.flags

-# Most of the flags in this file are duplicated to refer to both the pre- and
-# post-jarjar remapping versions of the class names. This enables the same
-# config file to be used whether jarjar is enabled or not.
+# Don't rename anything, it makes stack traces unintelligible. We only allow the
+# obfuscation pass to run so that we can discard attributes like local variable
+# tables.
+-keepnames class *** { *; }
 
+# Keep source file and line number information for stack traces.
+-keepattributes SourceFile,LineNumberTable
+
+# Keep all runtime visible annotations.
+-keepattributes RuntimeVisibleAnnotations
+
+# Disable optimization as this causes proguard to remove seemingly random stuff,
+# including things explicitly kept in this configuration.
+-dontoptimize
 
 # Keep the factory and its public members; it's the main entry point used by the
 # framework.
 -keep class com.android.webview.chromium.WebViewChromiumFactoryProvider {
     public *;
 }
 
-# Keep the native methods bound to plat_support.
--keepclasseswithmembers class com.android.webview.chromium.** {
+# Keep JNI interfaces.
+-keepclasseswithmembers class com.android.webview.chromium.**,org.chromium.** {

[dgn, 2015/07/02 16:10:00]

Why not the grouped format like we do in chrome?

-keepclasseswithmembers class com.android.webview.chromium.**,org.chromium.** {
  @**.AccessedByNative <fields>;
  @**.CalledByNative <methods>;
  @**.CalledByNativeUnchecked <methods>;
  native <methods>;
}

+  @**.AccessedByNative <fields>;
+}
+-keepclasseswithmembers class com.android.webview.chromium.**,org.chromium.** {
+  @**.CalledByNative <methods>;
+}
+-keepclasseswithmembers class com.android.webview.chromium.**,org.chromium.** {
+  @**.CalledByNativeUnchecked <methods>;
+}
+-keepclasseswithmembers class com.android.webview.chromium.**,org.chromium.** {
   native <methods>;
 }
 
-# Keep everything related to the org.chromium JNI interface.
--keepclasseswithmembers class com.android.org.chromium.** {
-  @**.AccessedByNative <fields>;
-}
--keepclasseswithmembers class com.android.org.chromium.** {
-  @**.CalledByNative <methods>;
-}
--keepclasseswithmembers class com.android.org.chromium.** {
-  @**.CalledByNativeUnchecked <methods>;
-}
--keepclasseswithmembers class com.android.org.chromium.** {
-  native <methods>;
+# Keep things explicitly marked as used by reflection
+-keepclasseswithmembers class com.android.webview.chromium.**,org.chromium.** {
+  @**.UsedByReflection *;
 }
 
-# Keep methods which get bound to JS interfaces via reflection.
--keepclasseswithmembers class com.android.org.chromium.** {
-  @**.JavascriptInterface <methods>;
-}
+# Linker dynamically casts to $TestRunner when running tests. We don't run these
+# tests in WebView.
+-dontnote org.chromium.base.library_loader.Linker$TestRunner
 
-# Silence notes caused by use of @VisibleForTesting inside guava. This doesn't
-# happen when using jarjar because @VisibleForTesting gets renamed as well.
--dontnote com.google.common.annotations.VisibleForTesting
+# Don't note about the API 21 compatibility code which references various
+# hidden APIs via reflection.
+-dontnote com.android.webview.chromium.WebViewDelegateFactory$Api21CompatibilityDelegate
+
+# DefaultAndroidKeyStore uses reflection to access internal OpenSSL state.
+-dontnote org.chromium.net.DefaultAndroidKeyStore
 
 # MediaPlayerBridge uses reflection to access internal metadata.
--dontnote com.android.org.chromium.media.MediaPlayerBridge
-
-# AndroidKeyStore uses reflection to access internal OpenSSL state.
--dontnote com.android.org.chromium.net.AndroidKeyStore
-
-# TraceEvent uses reflection to access internal trace info.
--dontnote com.android.org.chromium.content.common.TraceEvent
+-dontnote org.chromium.media.MediaPlayerBridge
 
 # ProxyChangeListener$ProxyReceiver uses reflection to access internal
 # android.net.ProxyProperties.
--dontnote com.android.org.chromium.net.ProxyChangeListener$ProxyReceiver
+-dontnote org.chromium.net.ProxyChangeListener$ProxyReceiver
 
-# com.android.org.chromium.content.app.Linker dynamically casts to $TestRunner
-# when running tests. We don't run these tests in WebView.
--dontnote com.android.org.chromium.content.app.Linker$TestRunner
-
-# We need to keep these explicitly as they are parameters to methods which

[sgurun-gerrit only, 2015/07/06 17:37:24]

Why don't we need this section anymore? 

[Torne, 2015/07/07 10:56:59]

The descriptor classes are always referenced (by the methods that use them) and
so can't actually be removed anyway - the only reason they needed to be kept
before was apparently because Proguard is concerned that they might be *renamed*
during the obfuscation phase which would change the JNI method signatures and
break the JNI interface. For some reason (proguard isn't very clever) it warns
about this even when you are using -dontobfuscate to completely prevent all
renamings.

However, we are now allowing obfuscation but explicitly forcing it to keep all
the names the same with the global -keepnames wildcard, and so it no longer
warns about these things because -keepnames is sufficient.

-# are entry points via @calledByNative.
--keep class com.android.org.chromium.ui.autofill.AutofillSuggestion
--keep class com.android.org.chromium.content.browser.ContentVideoViewClient
--keep class com.android.org.chromium.ui.ColorSuggestion
--keep class com.android.org.chromium.content.browser.input.DateTimeSuggestion
--keep class com.android.org.chromium.content.browser.ContentViewCore$JavaScriptCallback
--keep class com.android.org.chromium.content_public.browser.NavigationController
-
-# Keep these classes as they are parameters to methods that are native entry points.
--keep class com.android.org.chromium.android_webview.AwBrowserContext
--keep class com.android.org.chromium.base.library_loader.Linker$LibInfo
-
-# Keep this class and members as accessed via reflection
--keep class com.android.webview.chromium.Drp {
-  public *;
+# Silence warnings about reflection used to check for onShow/HideCustomView.
+# This class is not really kept since it's in a library jar.
+-keep class android.webkit.WebChromeClient {
+  void onShowCustomView(...);
+  void onHideCustomView();
 }
 
-# Keep finalizer stuff from google-common used via reflection
--keepclassmembers class com.android.org.chromium.com.google.common.** {
-  *** finalizeReferent();
-}
--keepclassmembers class com.android.org.chromium.com.google.common.** {
-  *** startFinalizer(java.lang.Class,java.lang.Object);
+# Accessed via reflection
+-keep class com.android.webview.chromium.Drp {
+  public java.lang.String KEY;
 }
 
-# Keep support framework support for SmartClip.
+# Keep framework support for SmartClip.
 -keep class com.android.webview.chromium.WebViewChromium {
   public void extractSmartClipData(int,int,int,int);
   public void setSmartClipResultHandler(android.os.Handler);
 }
 
-# We need to explicitly keep classes and constructors referenced only in
-# layout resources.
--keep class com.android.org.chromium.ui.ColorPickerAdvanced {
-  <init>(...);
+# Ignore notes about the support library's use of reflection.
+-dontnote android.support.**
+
+# Keep all enum values and valueOf methods. See
+# http://proguard.sourceforge.net/index.html#manual/examples.html
+# for the reason for this. Also, see http://crbug.com/248037.
+-keepclassmembers enum * {
+    public static **[] values();
+    public static ** valueOf(java.lang.String);
 }
-
--keep class com.android.org.chromium.ui.ColorPickerSimple {
-  <init>(...);
-}
-
--keep class com.android.org.chromium.ui.ColorPickerMoreButton {
-  <init>(...);
-}