Fix placeholder clipping issue

Summary:
Problem: The first ReactTextInputShadowNode layout  calculation didn't consider the placeholder. When the layout with placeholder was actually being measured, its height was constraint by the previously calculated height, causing long placeholder content to be clipped.
Fix: Access the placeholder property in ReactTextInputShadowNode, set the dummyEditText's hint with placeholder before ReactTextInputShadowNode's first measurement.

Reviewed By: mdvacca

Differential Revision: D8903108

fbshipit-source-id: 8f3e518d0395ac875807f9ea989a0b5bbe4b2a26

Author: Jiaqi Wu

ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactTextInputShadowNode.java

@@ -41,9 +41,11 @@ public class ReactTextInputShadowNode extends ReactBaseTextShadowNode
   private @Nullable ReactTextInputLocalData mLocalData;
 
   @VisibleForTesting public static final String PROP_TEXT = "text";
+  @VisibleForTesting public static final String PROP_PLACEHOLDER = "placeholder";
 
   // Represents the {@code text} property only, not possible nested content.
   private @Nullable String mText = null;
+  private @Nullable String mPlaceholder = null;
 
   public ReactTextInputShadowNode() {
     mTextBreakStrategy = (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) ?
@@ -148,8 +150,9 @@ public long measure(
       }
     }
 
-
-    editText.measure(
+     // make sure the placeholder content is also being measured
+     editText.setHint(getPlaceholder());
+     editText.measure(
         MeasureUtil.getMeasureSpec(width, widthMode),
         MeasureUtil.getMeasureSpec(height, heightMode));
 
@@ -193,6 +196,16 @@ public void setText(@Nullable String text) {
     return mText;
   }
 
+  @ReactProp(name = PROP_PLACEHOLDER)
+  public void setPlaceholder(@Nullable String placeholder) {
+    mPlaceholder = placeholder;
+    markUpdated();
+  }
+
+  public @Nullable String getPlaceholder() {
+    return mPlaceholder;
+  }
+
   @Override
   public void setTextBreakStrategy(@Nullable String textBreakStrategy) {
     if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {