[change] Default flex-basis value of Views

React Native has an implementation of flexbox that does not quite follow the
W3C spec for flexbox. Previously, React Native for Web attempted to replicate
the React Native rendering by setting flexBasis to 0%. However, this created
its own problems where views could collapse down to 0px in height on the web.
This patch relies sets the default flexBasis back to 'auto'. This will cause
different rendering inconsistencies with React Native, which can be addressed
by making changes to existing React Native styles. And ultimately, it is up to
Yoga to correct its flexbox implementation.

Fix necolas#1640
Fix necolas#1604
Fix necolas#1264
Close necolas#1265

src/exports/AppRegistry/__tests__/__snapshots__/index-test.js.snap

@@ -11,7 +11,7 @@ input::-webkit-inner-spin-button,input::-webkit-outer-spin-button,input::-webkit
 [stylesheet-group=\\"1\\"]{}
 .css-view-1dbjc4n{-ms-flex-align:stretch;-ms-flex-direction:column;-ms-flex-negative:0;-ms-flex-preferred-size:auto;-webkit-align-items:stretch;-webkit-box-align:stretch;-webkit-box-direction:normal;-webkit-box-orient:vertical;-webkit-flex-basis:auto;-webkit-flex-direction:column;-webkit-flex-shrink:0;align-items:stretch;border:0 solid black;box-sizing:border-box;display:-webkit-box;display:-moz-box;display:-ms-flexbox;display:-webkit-flex;display:flex;flex-basis:auto;flex-direction:column;flex-shrink:0;margin-bottom:0px;margin-left:0px;margin-right:0px;margin-top:0px;min-height:0px;min-width:0px;padding-bottom:0px;padding-left:0px;padding-right:0px;padding-top:0px;position:relative;z-index:0;}
 [stylesheet-group=\\"2\\"]{}
-.r-flex-13awgt0{-ms-flex-negative:1;-ms-flex-positive:1;-ms-flex-preferred-size:0%;-webkit-box-flex:1;-webkit-flex-basis:0%;-webkit-flex-grow:1;-webkit-flex-shrink:1;flex-basis:0%;flex-grow:1;flex-shrink:1;}
+.r-flex-13awgt0{-ms-flex-negative:1;-ms-flex-positive:1;-webkit-box-flex:1;-webkit-flex-grow:1;-webkit-flex-shrink:1;flex-grow:1;flex-shrink:1;}
 [stylesheet-group=\\"2.2\\"]{}
 .r-pointerEvents-12vffkv>*{pointer-events:auto;}
 .r-pointerEvents-12vffkv{pointer-events:none!important;}"

src/exports/StyleSheet/__tests__/createReactDOMStyle-test.js

@@ -42,7 +42,6 @@ describe('StyleSheet/createReactDOMStyle', () => {
   describe('flexbox styles', () => {
     test('flex: -1', () => {
       expect(createReactDOMStyle({ flex: -1 })).toEqual({
-        flexBasis: 'auto',
         flexGrow: 0,
         flexShrink: 1
       });
@@ -51,24 +50,21 @@ describe('StyleSheet/createReactDOMStyle', () => {
     test('flex: 0', () => {
       expect(createReactDOMStyle({ flex: 0 })).toEqual({
         flexGrow: 0,
-        flexShrink: 0,
-        flexBasis: '0%'
+        flexShrink: 0
       });
     });
 
     test('flex: 1', () => {
       expect(createReactDOMStyle({ flex: 1 })).toEqual({
         flexGrow: 1,
-        flexShrink: 1,
-        flexBasis: '0%'
+        flexShrink: 1
       });
     });
 
     test('flex: 10', () => {
       expect(createReactDOMStyle({ flex: 10 })).toEqual({
         flexGrow: 10,
-        flexShrink: 1,
-        flexBasis: '0%'
+        flexShrink: 1
       });
     });
 
@@ -95,8 +91,7 @@ describe('StyleSheet/createReactDOMStyle', () => {
       // can flex-shrink override the 'flex' expansion?
       expect(createReactDOMStyle({ flex: 1, flexShrink: 2 })).toEqual({
         flexGrow: 1,
-        flexShrink: 2,
-        flexBasis: '0%'
+        flexShrink: 2
       });
     });
   });

src/exports/StyleSheet/createReactDOMStyle.js

@@ -106,15 +106,12 @@ const createReactDOMStyle = style => {
           if (value > 0) {
             resolvedStyle.flexGrow = value;
             resolvedStyle.flexShrink = 1;
-            resolvedStyle.flexBasis = '0%';
           } else if (value === 0) {
             resolvedStyle.flexGrow = 0;
             resolvedStyle.flexShrink = 0;
-            resolvedStyle.flexBasis = '0%';
           } else if (value === -1) {
             resolvedStyle.flexGrow = 0;
             resolvedStyle.flexShrink = 1;
-            resolvedStyle.flexBasis = 'auto';
           }
           break;
         }