Well, if you have JailBroken your iPhone or iPad, there’s a good news for you. Ryan Petrich, who is a famous iPhone hacker has developed a tweak which lets you change your default browser. By Default, Apple has made mobile Safari deeply integrated into the iOS which means you can’t change it manually from settings. But this tweak would allow you to do that. All you have to do is to install the tweak via Cydia.
The tweak is called BrowserChooser. In fact, in addition to Chrome, there are various other browsers available to choose from. The options for default browsers are Chrome, Dolphin, Safari, iCab Mobile and Atomic Browser. Once you have chosen Chrome as your default browser, it doesn’t mean you couldn’t revert back. You can always do it from the BrowserChooser settings from settings.app. 
Perhaps, BrowserChooser is not the complete solution. At many places, mobile Safari might be invoked to open the url. But this tweak would work in almost across all applications. If you want to install the tweak, Go to Cydia>Sources>Edit>Add Source> “http://rpetri.ch/repo”. And wait until entire bundle of repositories is downloaded to search.