Add trace events to View#dispatchTouchEvent and RecyclerView#scrollStep

In local testing, View#dispatchTouchEvent and RecyclerView#scrollStep
take up a large chunk of time under Choreographer callbacks and are
not currently captured in traces for the scroll jank dashboard.

Hopefully, adding these trace events will clarify at least some of
the jank currently attributed to "Choreographer(java_views=)"

RecyclerView#scrollStep is a package-private method in AndroidX that
isn't part of the View API, so required some minor changes to the
Bytecode rewriter to support methods missing from some class
hierarchies.

Bug: 1357024
Change-Id: I73f8a7c733501e69b744e3315bba9360819fe3a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3876627
Reviewed-by: Mohamed Heikal <mheikal@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1044158}
NOKEYCHECK=True
GitOrigin-RevId: 85144e544dcecdc6928a86bc381ac08970953e2f

android/bytecode/java/org/chromium/bytecode/EmptyOverrideGeneratorClassAdapter.java

@@ -75,6 +75,7 @@ public void visitEnd() {
      */
     private void writeOverrideCode(
             MethodVisitor mv, final int access, final String name, final String descriptor) {
+        assert access != 0;
         Type[] argTypes = Type.getArgumentTypes(descriptor);
         Type returnType = Type.getReturnType(descriptor);
 

android/bytecode/java/org/chromium/bytecode/ParentMethodCheckerClassAdapter.java

@@ -6,6 +6,8 @@
 
 import static org.objectweb.asm.Opcodes.ACC_FINAL;
 import static org.objectweb.asm.Opcodes.ACC_PRIVATE;
+import static org.objectweb.asm.Opcodes.ACC_PROTECTED;
+import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
 import static org.objectweb.asm.Opcodes.ASM7;
 
 import org.objectweb.asm.ClassVisitor;
@@ -19,7 +21,7 @@
  * methods remain then we recurse on the class's superclass.
  */
 class ParentMethodCheckerClassAdapter extends ClassVisitor {
-    private static final String OBJECT_CLASS_DESCRIPTOR = "java.lang.Object";
+    private static final String OBJECT_CLASS_DESCRIPTOR = "java/lang/Object";
 
     private final ArrayList<MethodDescription> mMethodsToCheck;
     private final ClassLoader mJarClassLoader;
@@ -62,8 +64,12 @@ public MethodVisitor visitMethod(
             // This class contains methodToCheck.
             boolean isMethodPrivate = (access & ACC_PRIVATE) == ACC_PRIVATE;
             boolean isMethodFinal = (access & ACC_FINAL) == ACC_FINAL;
+            boolean isMethodPackagePrivate =
+                    (access & (ACC_PUBLIC | ACC_PROTECTED | ACC_PRIVATE)) == 0;
+
             // If the method is private or final then don't create an override.
-            methodToCheck.shouldCreateOverride = !isMethodPrivate && !isMethodFinal;
+            methodToCheck.shouldCreateOverride =
+                    !isMethodPrivate && !isMethodFinal && !isMethodPackagePrivate;
         }
 
         return super.visitMethod(access, name, descriptor, signature, exceptions);
@@ -72,6 +78,15 @@ public MethodVisitor visitMethod(
     @Override
     public void visitEnd() {
         if (mIsCheckingObjectClass) {
+            // We support tracing methods that are defined in classes that are derived from View,
+            // but are not defined in View itself. If we've reached the Object class in the
+            // hierarchy, it means the method doesn't exist in this hierarchy, so don't override it,
+            // and stop looking for it.
+            for (MethodDescription method : mMethodsToCheck) {
+                if (method.shouldCreateOverride == null) {
+                    method.shouldCreateOverride = false;
+                }
+            }
             return;
         }
 

android/bytecode/java/org/chromium/bytecode/TraceEventAdder.java

@@ -71,9 +71,12 @@ protected boolean shouldRewriteClass(String classPath) {
     @Override
     protected boolean shouldRewriteClass(ClassReader classReader) {
         mMethodsToTrace = new ArrayList<>(Arrays.asList(
+                new MethodDescription(
+                        "dispatchTouchEvent", "(Landroid/view/MotionEvent;)Z", Opcodes.ACC_PUBLIC),
                 new MethodDescription("draw", "(Landroid/graphics/Canvas;)V", Opcodes.ACC_PUBLIC),
                 new MethodDescription("onMeasure", "(II)V", Opcodes.ACC_PROTECTED),
-                new MethodDescription("onLayout", "(ZIIII)V", Opcodes.ACC_PROTECTED)));
+                new MethodDescription("onLayout", "(ZIIII)V", Opcodes.ACC_PROTECTED),
+                new MethodDescription("scrollStep", "(II[I)V", 0)));
 
         // This adapter will modify mMethodsToTrace to indicate which methods already exist in the
         // class and which ones need to be overridden. In case the class is not an Android view