Bug 709230 part 2 - Optimize Java .class files with ProGuard. r=dougt

config/android-common.mk

@@ -48,6 +48,7 @@ endif
 DX=$(ANDROID_PLATFORM_TOOLS)/dx
 AAPT=$(ANDROID_PLATFORM_TOOLS)/aapt
 APKBUILDER=$(ANDROID_SDK)/../../tools/apkbuilder
+PROGUARD=java -jar $(ANDROID_SDK)/../../tools/proguard/lib/proguard.jar
 ZIPALIGN=$(ANDROID_SDK)/../../tools/zipalign
 
 ifdef JARSIGNER

mobile/android/base/Makefile.in

@@ -586,7 +586,13 @@ classes.dex: $(FENNEC_JAVA_FILES) $(FENNEC_PP_JAVA_FILES) $(SYNC_JAVA_FILES) $(S
 	$(NSINSTALL) -D classes
 	$(JAVAC) $(JAVAC_FLAGS) -d classes $(addprefix $(srcdir)/,$(SYNC_THIRDPARTY_JAVA_FILES))
 	$(JAVAC) $(JAVAC_FLAGS) -Xlint:all,-deprecation,-fallthrough -d classes -classpath classes $(addprefix $(srcdir)/,$(FENNEC_JAVA_FILES)) $(FENNEC_PP_JAVA_FILES) $(addprefix $(srcdir)/,$(SYNC_JAVA_FILES)) $(SYNC_PP_JAVA_FILES) R.java
-	$(DX) --dex --output=$@ classes
+	$(PROGUARD) @$(topsrcdir)/mobile/android/config/proguard.cfg \
+			-injars classes \
+			-outjars classes-proguarded \
+			-libraryjars $(ANDROID_SDK)/android.jar
+	# ProGuard may optimize away local variables, so dx --no-locals to ignore
+	# debug symbols for missing local variables.
+	$(DX) --dex --output=$@ --no-locals classes-proguarded
 
 PP_RES_XML=$(SYNC_PP_RES_XML)
 

mobile/android/config/proguard.cfg

@@ -0,0 +1,98 @@
+#
+# Rules from Google's example proguard.cfg in the Android SDK:
+# android-sdk-macosx/tools/lib/proguard.cfg
+#
+
+# TODO: We can remove -dontskipnonpubliclibraryclasses for ProGuard >= 4.5
+# because it is enabled by default.
+-dontskipnonpubliclibraryclasses
+-dontpreverify
+-verbose
+
+# Preserve all fundamental application classes.
+-keep public class * extends android.app.Activity
+-keep public class * extends android.app.Application
+-keep public class * extends android.app.Service
+-keep public class * extends android.content.BroadcastReceiver
+-keep public class * extends android.content.ContentProvider
+-keep public class * extends android.app.backup.BackupAgentHelper
+-keep public class * extends android.preference.Preference
+
+# Preserve all native method names and the names of their classes.
+-keepclasseswithmembernames class * {
+    native <methods>;
+}
+
+# Preserve all classes that have special context constructors, and the
+# constructors themselves.
+-keepclasseswithmembers class * {
+    public <init>(android.content.Context, android.util.AttributeSet);
+}
+
+# Preserve all classes that have special context constructors, and the
+# constructors themselves.
+-keepclasseswithmembers class * {
+    public <init>(android.content.Context, android.util.AttributeSet, int);
+}
+
+-keepclassmembers class * extends android.app.Activity {
+   public void *(android.view.View);
+}
+
+# Preserve the special static methods that are required in all enumeration
+# classes.
+-keepclassmembers enum * {
+    public static **[] values();
+    public static ** valueOf(java.lang.String);
+}
+
+#
+# Rules from ProGuard's Android example:
+# http://proguard.sourceforge.net/manual/examples.html#androidapplication
+#
+
+# Switch off some optimizations that trip older versions of the Dalvik VM.
+# https://code.google.com/p/android/issues/detail?id=964
+-optimizations !code/simplification/cast
+
+# Preserve all View implementations, their special context constructors, and
+# their setters.
+-keep public class * extends android.view.View {
+    public <init>(android.content.Context);
+    public <init>(android.content.Context, android.util.AttributeSet);
+    public <init>(android.content.Context, android.util.AttributeSet, int);
+    public void set*(...);
+}
+
+# Preserve the special fields of all Parcelable implementations.
+-keepclassmembers class * implements android.os.Parcelable {
+    static android.os.Parcelable$Creator CREATOR;
+}
+
+# Preserve static fields of inner classes of R classes that might be accessed
+# through introspection.
+-keepclassmembers class **.R$* {
+    public static <fields>;
+}
+
+#
+# Mozilla-specific rules
+#
+
+# Preserve public classes and methods accessed from C++ JNI.
+-keep public class org.mozilla.gecko.** { public *; }
+
+# Google defaults to 5 passes, but Fennec benefits from up to 9-10 passes.
+-optimizationpasses 10
+
+# Disable obfuscation because it makes exception stack traces more
+# difficult to debug. Plus Firefox's code is already open-source.
+-dontobfuscate
+
+# Silence warnings about "Note: duplicate definition of library class".
+-dontnote **,!org.mozilla.**
+
+# Allow private members to be made public to improve method inlining.
+# TODO: Enable -allowaccessmodification optimizations for ProGuard >= 4.6.
+# These optimizations trigger a ProGuard 4.4 bug when inlining private methods.
+##-allowaccessmodification