[Downloads] Add a horizontal material-styled ProgressBar

chrome/android/java/res/values/colors.xml

Index: chrome/android/java/res/values/colors.xml
diff --git a/chrome/android/java/res/values/colors.xml b/chrome/android/java/res/values/colors.xml
index d0dd150f410181be2c18a168553751d7615fb4d2..dbc2e4dd4214d5cd88e5dfbf1fad465610418e69 100644
--- a/chrome/android/java/res/values/colors.xml
+++ b/chrome/android/java/res/values/colors.xml
@@ -124,8 +124,10 @@
     <!-- Progress Bar colors -->
     <color name="progress_bar_foreground">@color/light_active_color</color>
     <color name="progress_bar_foreground_white">@android:color/white</color>
+    <color name="progress_bar_secondary">@color/google_grey_600</color>
     <color name="progress_bar_background">#3d4386f7</color>
     <color name="progress_bar_background_white">#4d000000</color>
+    <color name="progress_bar_default_throbber">#7fffffff</color>
 
     <!-- Theme colors. Also used for toolbar background -->
     <color name="incognito_primary_color">#505050</color>