[protobuf] Convert thumbnail_cache_entry from nano to lite

This is the first CL in a sequence that converts all java
protobuf uses from nano to lite. It disables one proguard
optimization that breaks with lite-generated code.

Bug: 782237
Change-Id: Ifed32f216dacad69c1f32e903d8d30070070404b
Reviewed-on: https://chromium-review.googlesource.com/808684Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Jan Krcal <jkrcal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543317}

build/android/gyp/proguard.py

@@ -13,6 +13,7 @@ from util import proguard_util
 
 
 _DANGEROUS_OPTIMIZATIONS = [
+    "class/unboxing/enum",
     # See crbug.com/625992
     "code/allocation/variable",
     # See crbug.com/625994

chrome/android/BUILD.gn

@@ -278,6 +278,7 @@ android_library("chrome_java") {
     "//third_party/gif_player:gif_player_java",
     "//third_party/jsr-305:jsr_305_javalib",
     "//third_party/leakcanary:leakcanary_java",
+    "//third_party/protobuf:protobuf_lite_javalib",
     "//ui/android:ui_java",
     "//ui/base/mojo:mojo_bindings_java",
     "//ui/gfx/geometry/mojo:mojo_java",
@@ -413,6 +414,7 @@ proto_java_library("thumbnail_cache_entry_proto_java") {
   sources = [
     "$proto_path/thumbnail_cache_entry.proto",
   ]
+  generate_lite = true
 }
 
 java_cpp_template("resource_id_javagen") {

chrome/android/java/src/org/chromium/chrome/browser/widget/ThumbnailDiskStorage.java

@@ -14,7 +14,7 @@ import android.support.v4.util.AtomicFile;
 import android.support.v4.util.Pair;
 import android.text.TextUtils;
 
-import com.google.protobuf.nano.MessageNano;
+import com.google.protobuf.ByteString;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
@@ -259,14 +259,13 @@ public class ThumbnailDiskStorage implements ThumbnailGeneratorCallback {
         for (File file : cachedFiles) {
             AtomicFile atomicFile = new AtomicFile(file);
             try {
-                ThumbnailEntry entry =
-                        MessageNano.mergeFrom(new ThumbnailEntry(), atomicFile.readFully());
-                if (entry.contentId == null) continue;
+                ThumbnailEntry entry = ThumbnailEntry.parseFrom(atomicFile.readFully());
+                if (!entry.hasContentId()) continue;
 
-                String contentId = entry.contentId.id;
-                if (entry.sizePx == null) continue;
+                String contentId = entry.getContentId().getId();
+                if (!entry.hasSizePx()) continue;
 
-                int iconSizePx = entry.sizePx;
+                int iconSizePx = entry.getSizePx();
 
                 // Update internal cache state.
                 sDiskLruCache.add(Pair.create(contentId, iconSizePx));
@@ -312,17 +311,18 @@ public class ThumbnailDiskStorage implements ThumbnailGeneratorCallback {
             byte[] compressedBitmapBytes = baos.toByteArray();
 
             // Construct proto.
-            ThumbnailEntry newEntry = new ThumbnailEntry();
-            newEntry.contentId = new ContentId();
-            newEntry.contentId.id = contentId;
-            newEntry.sizePx = iconSizePx;
-            newEntry.compressedPng = compressedBitmapBytes;
+            ThumbnailEntry newEntry =
+                    ThumbnailEntry.newBuilder()
+                            .setContentId(ContentId.newBuilder().setId(contentId))
+                            .setSizePx(iconSizePx)
+                            .setCompressedPng(ByteString.copyFrom(compressedBitmapBytes))
+                            .build();
 
             // Write proto to disk.
             File newFile = new File(getThumbnailFilePath(contentId, iconSizePx));
             atomicFile = new AtomicFile(newFile);
             fos = atomicFile.startWrite();
-            fos.write(MessageNano.toByteArray(newEntry));
+            fos.write(newEntry.toByteArray());
             atomicFile.finishWrite(fos);
 
             // Update internal cache state.
@@ -374,12 +374,11 @@ public class ThumbnailDiskStorage implements ThumbnailGeneratorCallback {
 
             AtomicFile atomicFile = new AtomicFile(file);
             fis = atomicFile.openRead();
-            ThumbnailEntry entry =
-                    MessageNano.mergeFrom(new ThumbnailEntry(), atomicFile.readFully());
-            if (entry.compressedPng == null) return null;
+            ThumbnailEntry entry = ThumbnailEntry.parseFrom(atomicFile.readFully());
+            if (!entry.hasCompressedPng()) return null;
 
             bitmap = BitmapFactory.decodeByteArray(
-                    entry.compressedPng, 0, entry.compressedPng.length);
+                    entry.getCompressedPng().toByteArray(), 0, entry.getCompressedPng().size());
         } catch (IOException e) {
             Log.e(TAG, "Error while reading from disk.", e);
         } finally {

chrome/android/java/src/org/chromium/chrome/browser/widget/thumbnail_cache_entry.proto

@@ -11,6 +11,9 @@ package org.chromium.chrome.browser.widget;
 
 option java_package = "org.chromium.chrome.browser.widget";
 
+// TODO(jkrcal): Remove when protobuf 4.0 is out, https://crbug.com/800281.
+option optimize_for = LITE_RUNTIME;
+
 message ContentId {
   // Required.
   optional string id = 1;
@@ -24,4 +27,4 @@ message ThumbnailEntry {
   // Required.
   optional int32 size_px = 2;
   optional bytes compressed_png = 3;
-}
+}
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