[ui] use default member initializer in MockDrawableData

This is just for workaround the swarming output collapsion bug.

TBR=thakis@chromium.org, mohsen@chromium.org

Bug: 993247
Change-Id: Id1383aaf292419622997217276cb05faefcd4084
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1750477Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686377}

ui/touch_selection/touch_handle_unittest.cc

@@ -20,19 +20,13 @@ const float kDefaultDrawableSize = 10.f;
 const gfx::RectF kDefaultViewportRect(0, 0, 560, 1200);
 
 struct MockDrawableData {
-  MockDrawableData()
-      : orientation(TouchHandleOrientation::UNDEFINED),
-        alpha(0.f),
-        enabled(false),
-        visible(false),
-        rect(0, 0, kDefaultDrawableSize, kDefaultDrawableSize) {}
-  TouchHandleOrientation orientation;
-  float alpha;
+  TouchHandleOrientation orientation = TouchHandleOrientation::UNDEFINED;
+  float alpha = 0.f;
   bool mirror_horizontal;
   bool mirror_vertical;
-  bool enabled;
-  bool visible;
-  gfx::RectF rect;
+  bool enabled = false;
+  bool visible = false;
+  gfx::RectF rect{0, 0, kDefaultDrawableSize, kDefaultDrawableSize};
 };
 
 class MockTouchHandleDrawable : public TouchHandleDrawable {
@@ -63,9 +57,7 @@ class MockTouchHandleDrawable : public TouchHandleDrawable {
   // code refactoring is completed.
   float GetDrawableHorizontalPaddingRatio() const override { return 0; }
 
-  gfx::RectF GetVisibleBounds() const override {
-    return data_->rect;
-  }
+  gfx::RectF GetVisibleBounds() const override { return data_->rect; }
 
  private:
   MockDrawableData* data_;