Remove some more !IsModeMaterial code.

chrome/browser/ui/views/tabs/tab.cc

Index: chrome/browser/ui/views/tabs/tab.cc
diff --git a/chrome/browser/ui/views/tabs/tab.cc b/chrome/browser/ui/views/tabs/tab.cc
index ba7f628ea4eb6b8b5ee1a183928544c7910245e5..a94ac04a772b0c3f25bf929388da1f9c49144fac 100644
--- a/chrome/browser/ui/views/tabs/tab.cc
+++ b/chrome/browser/ui/views/tabs/tab.cc
@@ -1143,13 +1143,13 @@ void Tab::DataChanged(const TabRendererData& old) {
 }
 
 void Tab::PaintTab(gfx::Canvas* canvas, const gfx::Path& clip) {
-  const int kActiveTabFillId = IDR_THEME_TOOLBAR;
-  const bool has_custom_image =
-      GetThemeProvider()->HasCustomImage(kActiveTabFillId);
+  const int kActiveTabFillId =
+      GetThemeProvider()->HasCustomImage(IDR_THEME_TOOLBAR) ? IDR_THEME_TOOLBAR
+                                                            : 0;
   const int y_offset = -GetLayoutInsets(TAB).top();
   if (IsActive()) {
     PaintTabBackgroundUsingFillId(canvas, canvas, true, kActiveTabFillId,
-                                  has_custom_image, y_offset);
+                                  y_offset);
   } else {
     PaintInactiveTabBackground(canvas, clip);
 
@@ -1158,7 +1158,7 @@ void Tab::PaintTab(gfx::Canvas* canvas, const gfx::Path& clip) {
       canvas->SaveLayerAlpha(gfx::ToRoundedInt(throb_value * 0xff),
                              GetLocalBounds());
       PaintTabBackgroundUsingFillId(canvas, canvas, true, kActiveTabFillId,
-                                    has_custom_image, y_offset);
+                                    y_offset);
       canvas->Restore();
     }
   }
@@ -1215,20 +1215,24 @@ void Tab::PaintInactiveTabBackground(gfx::Canvas* canvas,
                                      const gfx::Path& clip) {
   bool has_custom_image;
   int fill_id = controller_->GetBackgroundResourceId(&has_custom_image);
-
-  // If the theme is providing a custom background image, then its top edge
-  // should be at the top of the tab. Otherwise, we assume that the background
-  // image is a composited foreground + frame image.  Note that if the theme is
-  // only providing a custom frame image, |has_custom_image| will be true, but
-  // we should use the |background_offset_| here.
   const ui::ThemeProvider* tp = GetThemeProvider();
-  const int y_offset = tp->HasCustomImage(fill_id) ? 0 : background_offset_.y();
 
   // We only cache the image when it's the default image and we're not hovered,
   // to avoid caching a background image that isn't the same for all tabs.

[Peter Kasting, 2016/10/21 21:07:50]

Nit: This comment is slightly confusing now that you broke the hover handling
into a separate block below.

Honestly, I'd probably just leave this structured as it was before (i.e. handle
hover in this block as well).  No changes to the current body of the block
should be needed (there's no need to detect hover and force the fill_id to zero
or anything).  And the resulting code winds up being shorter too.

[Evan Stade, 2016/10/21 22:11:12]

actually, there would be a need for 

  ..., has_custom_image ? fill_id : 0, ...

and since both fill_id and y_offset both aren't needed if !has_custom_image, I
thought it was clearer to separate.

[Peter Kasting, 2016/10/22 00:14:44]

Ah, you're right.  Man, I thought through this like three times and still didn't
see that that would, in fact, be needed.

Maybe just delete the blank line between these two chunks, then, since the
comment above describes both?

[Evan Stade, 2016/10/24 13:01:20]

incidentally, already done in latest patchset

-  if (has_custom_image || hover_controller_.ShouldDraw()) {
-    PaintTabBackgroundUsingFillId(canvas, canvas, false, fill_id,
-                                  has_custom_image, y_offset);
+  if (has_custom_image) {
+    // If the theme is providing a custom background image, then its top edge
+    // should be at the top of the tab. Otherwise, we assume that the background
+    // image is a composited foreground + frame image.  Note that if the theme
+    // is only providing a custom frame image, |has_custom_image| will be true,
+    // but we should use the |background_offset_| here.
+    const int y_offset =
+        tp->HasCustomImage(fill_id) ? 0 : background_offset_.y();
+    PaintTabBackgroundUsingFillId(canvas, canvas, false, fill_id, y_offset);
+    return;
+  }
+
+  if (hover_controller_.ShouldDraw()) {
+    PaintTabBackgroundUsingFillId(canvas, canvas, false, 0, 0);
     return;
   }
 
@@ -1249,14 +1253,12 @@ void Tab::PaintInactiveTabBackground(gfx::Canvas* canvas,
     gfx::Canvas tmp_canvas(size(), canvas->image_scale(), false);
     if (use_fill_and_stroke_images) {
       gfx::Canvas tmp_fill_canvas(size(), canvas->image_scale(), false);
-      PaintTabBackgroundUsingFillId(&tmp_fill_canvas, &tmp_canvas, false,
-                                    fill_id, false, y_offset);
+      PaintTabBackgroundUsingFillId(&tmp_fill_canvas, &tmp_canvas, false, 0, 0);
       g_image_cache->emplace_front(
           metadata, gfx::ImageSkia(tmp_fill_canvas.ExtractImageRep()),
           gfx::ImageSkia(tmp_canvas.ExtractImageRep()));
     } else {
-      PaintTabBackgroundUsingFillId(&tmp_canvas, &tmp_canvas, false, fill_id,
-                                    false, y_offset);
+      PaintTabBackgroundUsingFillId(&tmp_canvas, &tmp_canvas, false, 0, 0);
       g_image_cache->emplace_front(
           metadata, gfx::ImageSkia(),
           gfx::ImageSkia(tmp_canvas.ExtractImageRep()));
@@ -1279,7 +1281,6 @@ void Tab::PaintTabBackgroundUsingFillId(gfx::Canvas* fill_canvas,
                                         gfx::Canvas* stroke_canvas,
                                         bool is_active,
                                         int fill_id,
-                                        bool has_custom_image,
                                         int y_offset) {
   gfx::Path fill;
   SkPaint paint;
@@ -1296,7 +1297,7 @@ void Tab::PaintTabBackgroundUsingFillId(gfx::Canvas* fill_canvas,
     {
       gfx::ScopedCanvas clip_scoper(fill_canvas);
       fill_canvas->ClipPath(fill, true);
-      if (has_custom_image) {
+      if (fill_id != 0) {

[Peter Kasting, 2016/10/21 21:07:51]

Nit: To avoid the else reading like a double-negative, I would either write this
as "if (fill_id)", or else flip the conditional and reverse the arms.

[Evan Stade, 2016/10/21 22:11:12]

Done.

         gfx::ScopedCanvas scale_scoper(fill_canvas);
         fill_canvas->sk_canvas()->scale(scale, scale);
         fill_canvas->TileImageInt(*tp->GetImageSkiaNamed(fill_id),