Toolbar: Fix wrong location bar background color

The theme color for location bar background should come from a specified
tab, not the current theme color from TopUiThemeColorProvider. This
addresses the wrong color when multiple tabs are being presented
such as in tab switcher.

This CL makes TUTCP#calculateColor public to get the right theme color
for a given tab object.

Bug: 1157417, 1157433
Change-Id: I10c30a7fc93bf9a21b0d113847651c4138a3c02e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2589135Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837338}

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerImpl.java

@@ -805,8 +805,8 @@ public class LayoutManagerImpl implements LayoutManager, LayoutUpdateHost, Layou
         TopUiThemeColorProvider topUiTheme = mTopUiThemeColorProvider.get();
         layoutTab.initFromHost(topUiTheme.getBackgroundColor(tab), shouldStall(tab),
                 canUseLiveTexture, topUiTheme.getSceneLayerBackground(tab),
-                ToolbarColors.getTextBoxColorForToolbarBackground(
-                        mContext.getResources(), tab, topUiTheme.getThemeColor()),
+                ToolbarColors.getTextBoxColorForToolbarBackground(mContext.getResources(), tab,
+                        topUiTheme.calculateColor(tab, tab.getThemeColor())),
                 topUiTheme.getTextBoxBackgroundAlpha(tab));
 
         mHost.requestRender();

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/StaticLayout.java

@@ -374,8 +374,8 @@ public class StaticLayout extends Layout {
             return sToolbarTextBoxBackgroundColorForTesting;
         }
 
-        return ToolbarColors.getTextBoxColorForToolbarBackground(
-                mContext.getResources(), tab, mTopUiThemeColorProvider.get().getThemeColor());
+        return ToolbarColors.getTextBoxColorForToolbarBackground(mContext.getResources(), tab,
+                mTopUiThemeColorProvider.get().calculateColor(tab, tab.getThemeColor()));
     }
 
     @VisibleForTesting

chrome/browser/ui/android/theme/java/src/org/chromium/chrome/browser/theme/TopUiThemeColorProvider.java

@@ -56,11 +56,11 @@ public class TopUiThemeColorProvider extends ThemeColorProvider {
         mTabObserver = new CurrentTabObserver(tabSupplier, new EmptyTabObserver() {
             @Override
             public void onDidChangeThemeColor(Tab tab, int themeColor) {
-                updateColor(tab, themeColor, false);
+                updateColor(tab, themeColor, true);
             }
         });
         tabSupplier.addObserver((tab) -> {
-            if (tab != null) updateColor(tab, tab.getThemeColor(), true);
+            if (tab != null) updateColor(tab, tab.getThemeColor(), false);
         });
         mActivityThemeColorSupplier = activityThemeColorSupplier;
         mIsTabletSupplier = isTabletSupplier;
@@ -80,7 +80,13 @@ public class TopUiThemeColorProvider extends ThemeColorProvider {
         mIsDefaultColorUsed = isUsingDefaultColor(tab, themeColor);
     }
 
-    private int calculateColor(Tab tab, int themeColor) {
+    /**
+     * Calculate theme color to be used for a given tab.
+     * @param tab Tab to get the theme color for.
+     * @param themeColor Initial color to calculate the theme color with.
+     * @return Final theme color for a given tab, with other signals taken into account.
+     */
+    public int calculateColor(Tab tab, int themeColor) {
         // This method is used not only for the current tab but also for
         // any given tab. Therefore it should not alter any class state.
         boolean isThemingAllowed = isThemingAllowed(tab);