Use metadata when launching WebAPKs.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
index 05eb9169f62e4dacc5bfc7ee434a5a581f6faad1..f4b93556da9273031662c703bbaf6728c74d5266 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
@@ -62,7 +62,7 @@ public class WebappActivity extends FullScreenActivity {
 
     private final WebappDirectoryManager mDirectoryManager;
 
-    private WebappInfo mWebappInfo;
+    protected WebappInfo mWebappInfo;
 
     private boolean mOldWebappCleanupStarted;
 
@@ -244,8 +244,12 @@ public class WebappActivity extends FullScreenActivity {
         return mWebappInfo;
     }
 
-    private void initializeWebappData() {
-        final int backgroundColor = ColorUtils.getOpaqueColor(mWebappInfo.backgroundColor(
+    protected void initializeWebappData() {
+        initializeSplashScreenWidgets(initializeWebappDataInternal());
+    }
+
+    protected int initializeWebappDataInternal() {
+        int backgroundColor = ColorUtils.getOpaqueColor(mWebappInfo.backgroundColor(
                 ApiCompatibilityUtils.getColor(getResources(), R.color.webapp_default_bg)));
 
         mSplashScreen = new FrameLayout(this);
@@ -261,11 +265,10 @@ public class WebappActivity extends FullScreenActivity {
         mWebappUma.recordSplashscreenThemeColor(mWebappInfo.hasValidThemeColor()
                 ? WebappUma.SPLASHSCREEN_COLOR_STATUS_CUSTOM
                 : WebappUma.SPLASHSCREEN_COLOR_STATUS_DEFAULT);

[pkotwicz, 2016/06/20 18:26:14]

This seems out of place. We should:
1) fetch the theme color from data storage
2) Log UMA with the theme color that was fetched from data storage

[Xi Han, 2016/06/22 15:55:28]

Good catch. Move the setThemeColor() before setBackgroundColor().

-
-        initializeSplashScreenWidgets(backgroundColor);
+        return backgroundColor;
     }
 
-    protected void initializeSplashScreenWidgets(final int backgroundColor) {
+    private void initializeSplashScreenWidgets(final int backgroundColor) {
         final Intent intent = getIntent();
         WebappRegistry.getWebappDataStorage(this, mWebappInfo.id(),
                 new WebappRegistry.FetchWebappDataStorageCallback() {